magic lantern sounds awesome, though very finicky. I‘m playing around with CHDK which is similar in its functionality, but targeting a different set of canon cameras, and it’s far less capable. I’d just love to be able to reuse my awesome canon RF lenses for other things, but that‘ll require a reverse engineering effort. I know that some people did that for canon EF, and mby one could build off that, but it’s probably a lot of effort still. I’ve seen the cinepi, and i find it very intriguing, but i don’t wanna have to spend lots of money on new lenses, because those i got already were too expensive, and if i go cheap (if thats possible at all), i might be loosing features i like. Still, awesome concept. I’ll have to try it eventually!

https://apertus.org/