The curl is really bad, like unusably bad, especially towards the end of the roll.

Have you ever used roll paper? In what use cases did you find it equivalent or superior to flat? Any problems with curling paper, see any paper waste from the core as it runs low?

Have you ever wrapped presents with rolled paper? Notice any issues with it? Think it would work well for a pile of documents?

Sounds like you're the one arguing from ignorance here

it also takes normal sheet paper. but it has an integrated cutter so the rolls enable A4 or A3 (us letter or 11x17), or any other length, or continuous from the same source.

permanent printheads are not really any better from a longevity standpoint. they still do degrade and need replacement. more often than not, that replacement either doesn't exist, hasn't been manufactured since the printer was a new model, or is prohibitively expensive and/or only available from random third-parties.

the last ink tank + separate printhead setup that you could very easily get tanks and printheads for was some old canon printers from 25+ years ago. the printheads were in a removable caddy, and that caddy was sold in stores with and alongside ink tanks.

printheads also need to be used, regularly. once you go a few weeks without printing, every day that you don't increases your chance those printheads will never print again. when the printhead is in the consumable, it gets replaced far easier and automatically on a cartridge swap. yes, that is at the expense of higher cost new consumables.

we've had to bin three brothers, two hp, an epson, and a canon over the twenty years because of bad and unreplaceable printheads. coincidentally we're currently using two salvaged hp printers that use the same cartridges as this 'open' printer, use refilled consumables, and the printers are old enough they don't scream and refuse to print if the color is empty--we can use and print black only.

the problem here with this project is they don't have their own printheads and cartridges, which means some of their code was either lifted from hp printers or reverse engineered; and they rely on hp as the only source for new consumables and printheads. hp would be very hostile to this project, so i hope they fully documented their entire process of development and are ready for the inevitable lawsuit.