Comment # 1 on bug 1151174 from Johannes Meixner

There is basically nothing what we (i.e. openSUSE) could do
in case of printer model specific issues,
cf. "Background Information" at
https://en.opensuse.org/SDB:How_to_Report_a_Printing_Issue
and
there is nothing at all what we (i.e. openSUSE) can do
in case of issues with printer models that need any kind
of proprietary stuff to work,
cf. "Printers with non-free driver software" at
https://en.opensuse.org/SDB:Printer_buying_guide

For such issues you need to get in contact with HPLIP upstream
https://developers.hp.com/hp-linux-imaging-and-printing
so that there is a direct communication between you
and the upstream authors, cf. "Background Information" at
https://en.opensuse.org/SDB:How_to_Report_a_Printing_Issue

FYI:
In particular regarding firmware upload related issues
with HPLIP you may have a look at the rather old
https://bugs.launchpad.net/hplip/+bug/187049
which shows that this kind of issues are not openSUSE specific
issues but permanent generic issues with HPLIP and such devices.