@Stratoscope thank you for such a detailed comment. We are fully aware of the topics you've mentioned. I'll try to cover all your questions in the following points:
1. Screenshot contrasts – we will be working on providing setting desired contrast in Luna just by selecting a predefined one from a drop-down menu. We are not there yet, because to make it working properly it is a little tricky thing. However, please keep in mind that the visual part of Luna is one of the most important parts of the whole projects to us (and for me personally). Right now we provide a "default" dark setting, that is suitable for working long hours in Luna without making your eyes tired (please note that we do not use gray, we use red-ish color scheme there).

2. We know that such settings are not the best for everyone, especially for developers older than about 40 years. We would our best to provide appropriate settings, so you can either increase the contrast or change the theme to white one (or write your custom theme from scratch). In fact, if you navigate right now to our theme settings you can already see some contrast settings. They do not work properly yet, but you can see that we are slowly working in that direction. However, we do not want to just "increase the contrast". There is a lot of people who prefer lower contrast, as we ship right now. We want to do it the right way, so you will have control and will be able to easily fine tune the GUI to your preferences.

3.I've read the research you mention. It states in particular, that when your irises are more closed, it is much easier for you to track corners and edges, however your eyes are getting tired easier. Working with white theme a whole day could be a pain, so we started with default dark theme. It is also affected by our personal preference, but as I described above, it is VERY important to us to make Luna easy to work with for everybody in all conditions, which also includes white, high-contrast themes. Please, keep in mind that it will need some time to develop. We are still a small team and we've got some high-priority things on our checklist right now, like improving the typechecking performance.

4. Our docs provide white PDF, but also the HTML version provides a white theme - just click on the "A" latter icon on top of the docs and switch to the light theme there! :)

5. Proportional fonts are a little tricky by definition. The question is - if you really want to use them when writing code. What I mean is that what you write above ndoes could be any code snippet. It could be just a function name, but could also be any expression like `2+2`. We are currently synchronizing the text editor font with nodes font, so if you use monospaced font in your editor, the same font will appear above the nodes. Do you think it is a wrong approach? If so, how would you change it? The best way to tell us about it is to create a github issue / discussion about it.

6. As I described above, we are small team of developers on a mission to bring something incredible for data processing. We are very open for any improvement suggestions. Any suggestsion regarding how the GUI looks like and how readible it is, is very, very important to us. This topic is tricky, because we want to provide flexibility over how the GUI looks like. We would be also very thankful for any help on helping us improve it. So if you tell more about what you think on github issues, we can continue the disusion there. We will tell you in detail what are our ideas and we could then choose the one that is the best (allowing everyone to set up the theme for hes own preferences).

Thank you once again and im looking forward to hearing from you! :)