Hi, I think that the new Cake and Ring are good tools to having the software taking shape, however I find myself not using them so often as it's still very intermediate. You should display a mask preview for the Cake refinement slider and put a refinement + mask preview for the Ring option too!

One should be able to choose how advanced to go with this "simple and visual" software, and still in the early stage, I take hours to grade in Photon entirely in spite of the fact that I take time myself!
I think your dedication to distinguish yourself from Resolve and 3D Lut Creator is remarkable but I would consider looking how the latter is complicated and simple at the same time (their C/L grids for instance whose algorythm can be "set" beforehand with a slider).

This being said in the video you find an example how I want to grade a sky but I can't really select all of it, but the fact you added an instant overlay preview so that I can choose where to click before I set a mask is salvation, it helps so much even if you were to alter a color in steps. I know I could get a better selection with DRB but it just makes so much sense to do it with HSL and having it super precise. Maybe you can allow a user to pin a second point (shift + click) that is combined to the first to define a final color range. I'm not suggesting you should be able to put more than two points and also alt + clicking to add a "subtraction point" but that may be an idea if it finds the context.

Lastly the software crashes on startup but if right click an image and open it in photon it says "can't open jpegs" but then Photon loads up and I can start working.