Mixing different toner particle sizes and compounds has ended in complete disaster for me in the past. I recall mixing and matching OEM with third party and then the toner not sticking to the paper properly. Guess where it goes if the toner does not end up on the paper and the printer thinks it did? It starts accumulating in the printer leading to a total disaster because now the printer never worked right after that.

Now I just buy my OEM toner used on eBay. Thats the secret. Find a semi new somewhat popular business class printer and keep an eye out for companies offloading their unused OEM toner.

> the toner refill kit is entirely passive and has no electrical contacts or other authentication

Yet.

It seems unlikely that HP will add DRM after the fact. Even if the printer has the hardware capability to enforce DRM, it isn't upon release, so you could simply keep it VLAN-ed off of the internet so it can't update its firmware to a version that begins enforcing the DRM chips. Adding DRM would also create a subpar UX where old, DRM-less HP refills stop working because the firmware thinks they're knockoffs.