### General comments

This works presents the result of an experimental wind tunnel study on the scaled hybrid-lambda rotor using four different control strategies. The amount of tests performed and the quality of the experiments is high and I would like to thank the authors for their efforts. I also think the scientific significance of this work is very good as the hybrid-lambda rotor concept and the different controller strategies here push the boundaries of what is currently available in academic literature and the authors make good recommendations for large-scale wind turbine controls from their work. Overall, I think this work is suitable for wind energy science and should be accepted after minor revisions.

I recommend the following main improvement for the manuscript:

1. The objective of the work is not aligned well between the abstract, introduction, and the conclusion, which becomes apparent when first reading the abstract, introduction, and then the conclusion before continuing with the rest of the paper. From reading the abstract the goal is to develop and apply control strategies on the MoWiTO and this objective is repeated in the introduction. However, the introduction doesn't include what type of controllers will be tested which makes it unclear to the reader what exactly the 3rd paragraph in the introduction is for (it doesn't connect that well to the rest of the introduction). Finally, in the conclusion emphasis is given how this experiment leads to recommendations for controller design for very large wind turbines. I think announcing this as an objective in the introduction would make it come less unexpectedly. I think most of this can be solved by rewriting the introduction. I recommend elaborating on the objective and connecting it to the earlier parts in the introduction.

A few smaller comments also apply more generally to the manuscript and are:

1. The resolution of the figures is quite small making it not pleasant to zoom in to see more detail as a reader. I would recommend exporting figures using a vector format.

2. The colour choice in figures is not always good. In black-and-white printing some colours are almost indistinguishable, such as baseline and FFLFB in figure 13. I also suspect that readers with a colour-vision deficiency would have difficulty distinguishing the different colours in most figures. I would recommend using scientific colour maps, as recommended by WES: https://zenodo.org/record/1243862

3. In the text, some lines in the figures are referred to by their colour instead of by their label. I think that this exacerbates the problem with the colour choice in the figures.

4. Not all lines in the figures are present in the legend and are sometimes only explained in the caption. I think that afraid this exacerbates the problem with the colour choice in the figures.

5. The captions of the figures currently have to explain more what is in the figures (also due to incomplete legends) so to understand the results I have to switch from the figure to the text and back a lot. It would improve readability if the captions would also include the main result to make the figures more interpretable on their own.

6. LUT1 and LUT2 are not very descriptive names for look-up tables, which made it slightly harder to follow some parts of the text. I think a more descriptive naming would  improved the flow of the text.

### Specific comments

1. Abstract:

    1. Line 2: "extreme loads" is usually associated with ultimate loads while it is also a trade-off with fatigue loads. I think either removing "extreme" or explicitly adding fatigue loads would be more complete.

2. Introduction:

    1. Line 17: The first paragraph would benefit from one or two citations.

    2. Line 18: "Rotors with a low-specific rating can capture more energy in light winds" is technically not correct. I think adding making it "relatively more energy" would read better.

    3. Line 30: Reading this paragraph, I feel like I wouldn't know at which paper to start for a good general overview of the Hybrid-Lambda concept because the two citations used are introduced rather late as simulation studies of the concept (not as fundamental papers explaining the concept). Maybe it's good to cite one of your works earlier in the paragraph so that readers have a clear citation which they can learn about the concept of Hybrid-Lambda.

3. Methodology

    1. The order of subsections and subsubsections is first an overview of the steady-state operating points, then the scaling considerations, then the torque controller, and then the pitch controller. After finishing the section on steady-state operating points I was expecting more information on the implementation of the controllers, as you already hint to some of the challenges that the hybrid-lambda concept poses for control. I would put the scaling considerations section somewhere else in the methodology so the control parts can be together.

    2. Line 171-178: This is a good summary of the scaling considerations which makes this section possible to follow for people with less exposure to wind tunnel testing.

    3. Line 201-216: I understand this scheme and think it's an interesting way to solve this problem but I had to reread this section a couple of times to convince myself that it works. I would recommend to rewrite this section and take the reader along in the process to make it more intuitive and understandable.

    4. Line 222: "Additionally, we tested a combination of the latter two versions (FFLFB)." I would combine this with the previous sentence because as a reader I expected 4 controllers to be listed in one sentence.

    5. Line 223-224: I think this is a creative and interesting approach. I would add a short explanation as to why this works. I guess the reasoning is that below the maximum rotor speed the PI controller always wants to speed up thus decrease the pitch but is then saturated by the minimum pitch angle.

4. Discussion

    1. I'm familiar with the work of Lazzerini et al (2025) and it would be helpful to see a comparison to your method. I see their work as completely letting go of the concept of tip speed ratio, or going towards a kind of Hybrid-Lambda control concept with an infinite number of TSRs instead of 2. Do you think that their control approach would work well for your rotor design? 

    2. In extension to that, their torque controllers also use the wind speed estimate. Do you think that that would have worked in your case too and I'm curious why you made the decision to not use the wind speed estimate in your torque controller.

5. Conclusions

    1. Line 558: "arranging" is too vague in this context and makes it hard to understand for a reader who has only read the abstract and introduction.

    2. The first two paragraphs of the conclusion are clear. However, the third and fourth paragraph discuss the transfer from the presented control strategy to a full-scale system and make a concluding remark of the work. I thought that the full-scale discussion seemed to stand on its own rather than be explicitly related to this study. The last paragraph could be made clearer by defining a more specific point. I would revise these sections by defining a main point you want to make and making the connection to your work clearer.

### Technical corrections

I have no technical corrections to recommend.

Overall

• This is an interesting investigation of a few control schemes in an experimental setting.  The control schemes are scaled and based on the Hybrid Lambda rotor.  The authors have put a lot of thought and effort into the scaling of the controller, but it's not clear how the algorithms will perform or need to be changed at full-scale.  The results are thoroughly presented, but clear takeaways and the impact of this work are unclear.

Major Comments

• If the main contribution of this controller is to achieve a higher power coefficient when the loads are constrained, this should be made clear early in the paper.  Is this outcome validated by the experiments?
• It is good to scale the maximum pitch rate, but in practice this should not be reached during normal operation.  Have you scaled the bandwidth of the pitch controller's response to a gust as well?
• It is unclear if there is an impact of this work outside of a Hybrid-lambda rotor.  Please elaborate.
• It is mentioned that at full scale, the root bending moment will have 1P oscillations, but at model scale, the 1 Hz filter on the RBM will remove this frequency. It seems like a different filtering method will be needed at larger scales.  What other considerations in the controller must be made when scaling up?
• In Fig 10, the FF controllers have a higher pitch angle, but the same speed and torque at the same wind speed.  How can you account for this? 
• One of the authors' conclusion is that a wind preview will be required?  That's kind of a strong statement given that load limiting control systems exist on modern turbines without preview measurement.
• While the results are presented in detail, a high-level summary would help the reader navigate the article more easily.  I'm not sure what to take way from these investigations. And I'm not sure what the benefits and drawbacks of each controller are.

Minor Comments

• The term "Control schedule" is unclear.  Are these steady state operating points? Or are they inputs to the turbine?  Which are inputs and which are outputs of the controller?  Also, Fig 1. is far from where it's introduced and the various U_* are not defined

Editorial Comments

• In Line 24, what is "it?"  Many sentences throughout this article start with it and this, which are not always clear.  Consider having this paper edited for grammar.
• There are a lot of variables and acronyms defined throughout this text.  It helps the reader if they are defined in captions or in a table at the start of the article.