Thanks for the answer!
Just bought a phomemo, looks like smart folks created a cups driver for it. (Ab)using dnsmasq and nginx is clever, will keep that in mind.
Perhaps not relevant in your case, but if you print qr, the caps of your links also affect the amount of data in the code:
rcmd@lemmy.world 2 days ago
Surprisingly, it works! I just checked it on my microservice, indeed now QRs are smaller. This is a lifesaver tip, thanks a bunch!