Yeah, the tl;dr is that people who did the amazing work of cracking the bootloader open, also, went for making the GSI ROMs actually usable. So... I it works by the way of patching the system image, by adding a service that deals with e-ink stuff (It works surprisingly well), and, alongside phhtreble patches, pretty much everything works (The only thing I have found to not work, is the Jack. But aside from that? Perfectly fine.).
And considering how niche the device is... I think, GSI was the only way in the first place. Considering how well it works. I mean, it would be nice to have actual proper rom, but... I will take what's given >:D
And considering how niche the device is... I think, GSI was the only way in the first place. Considering how well it works. I mean, it would be nice to have actual proper rom, but... I will take what's given >:D