Wow
Tested on my Poco X3. TLDR: barely functional but promising.
Settings: anything aside RAW10<->RAW16 show little effect on performance. "Raw video memory usage" seems to benefit from being maxed out but it's more a feeling than fact. You'll have to select "raw video" and exposure settings every time you switch from app's main screen (like switching between apps or entering settings). OIS can be activated but doesn't work in my case, thus the image is shaky. Focus control is kind of distributed strangely: 90% of slider is mapped to nearest 1m, the rest of focusing range is cramped in the tiny space at the right end. Nice for macro, I guess, not for anything else. AWB should be locked or it will affect the image otherwise.
Raw: I was able to get mostly reliable recording in all conditions at max crop (40% H/V, 2772x2082) at 24/25 fps for durations about up to 1-1,5 min. Was not testing for longer times because of huge file sizes and some quirks. I was able to record 4K-ish resolutions (4112x2082) outdoors (it's about 0°C now) but it drops frames starting from 15-20s indoors. Overheating? No framing guides for crop area - use your imagination looking at full sensor image feed. Raw images are initially written in chunks of 900 frames as zip archive somewhere in system folders (haven't found location yet). You have to manually unzip and transfer them as dngs in "manage videos" by tapping "queue" button. You can set the destination folder once at first conversion, I was not able to find this setting anywhere else, the only way to change this directory was to reinstall the app. And yeah, no sound at all yet.
Processing: transfer times are huge on my phone mostly because of USB2 transfer speed. Files are bulky, I filled 60GB of free space just with a dozen of clips. Considering buying TF card to unzip dngs and swapping it out to card reader (if projects goes well in this direction). AE2021 and Resolve 17 work well with dng sequences, Premiere 2021 refused to import. I had to rename dng sequence according to unique folder name manually because they were named with same base name - frame-#####.dng. There is some glitchy "transitional zone" between two 900-frame chunks where frames are randomly tossed to different chunks. At first I thought it was just frame dropouts but later I was able to reconstruct frame order manually at post - see image. Image quality is much better, especially at moderately high ISOs (800-1600). Compressed image degrades at this range - details are getting mushy, colors - muddy. Raw on the contrary has very manageable grain structure and highlight rolloff, lacks any sharpening. DR is better in a sense that you're getting more usable DR but it's far from being cinema camera wide - you should be careful with highlights, and the absence of any exposure assisting tools doesn't help at all.
Is it worth trying? Yes, I think. It's not the way you'd shoot something for fast turnarounds, or for a long duration. It's more an artistic experiment. The project is in a very early stage now but it's all about polishing interface and performance, adding useful features, improving general stability - the core idea is functional. I'm really happy to stumble upon this project - I haven't feel such joy and excitement since shooting photos with Nokia 808. Basically it's a 8mm raw camera you have no excuses not to carry with you all the time.