Your first photo looks eerily similar to a multiple aperture mask I made nearly 10 years ago. But I only used mine on a bright Moon and planets. It dims the image a little on my 8-in f/6 but takes away some irradiance so the image is "steadier", especially with turbulent air. So you cannot not see more details than without a mask but the steadier image is more pleasant. Of course, several notables here will tell you that the diffraction effects will do harm more than help but I do not find that to be the case. I'm no optician but aren't there some large professional scopes (Keck ?) that use segmented mirrors? Seems like diffration effects there would be horrendous.
Anyway, it is a quick, cheap and easy project and I don't see why it shouldn't work on solar. If the seeing is really bad you can cover up one or more aperture openings until it gets just right.
You might want to consider a light color so the mask isn't superheated by the Sun.
Go for it and report back!