> However, ink chemistry is not some straightforward mixing and the risks are largely downplayed by 3rd party ink manufacturers.
I'd be willing to accept that for systems where the ink cartridges and printheads are separate and third-party ink not up to spec can actually cause serious damage (e.g. clogged ink pipes, replacing or flushing these is a serious amount of work), but HP's consumer printers are almost exclusively made with combined inkhead/cartridges.
Well, I had a Canon BJC4300 with separate cartridges and printheads. These things burst if you don't use printer for some time and the ink dried and expanded. As a result, you'd have four color bands at the end of every line. So, no thank you, I'll prefer combined ones.
My decades old prints done with an HP500C are still intact and looking nice-ish and definitely legible. I don't want to get an old printed document a couple of years old and see it faded away.
Same for photos. I print photos for people and some of them are still looking almost new after 5-6 years, despite being printed with a mid-end "Ink Advantage" printer with dye inks.
For high volume, ephemeral prints, a 3d party ink can be OK, but these are my concerns, and I'm not willing to take the risks personally. Failing print heads and flooded printers are also not in my wish list, thanks.
A simple printer like an old 500C can be cleaned easily, but a more compact AIO with a duplexer cannot be cleaned after such event.
While tangential, I remember seeing HP's own, official black cartridge refill kits when 500C and 550C were new. I didn't see them after.
I'd be willing to accept that for systems where the ink cartridges and printheads are separate and third-party ink not up to spec can actually cause serious damage (e.g. clogged ink pipes, replacing or flushing these is a serious amount of work), but HP's consumer printers are almost exclusively made with combined inkhead/cartridges.