Comment # 1 on bug 1029021 from Johannes Meixner

Ghostscript does not communicate to the printer (via the USB device).
Ghostscript is called within a pipe of various other
filtering programs like
... producer_program | Ghostscript | consumer_program ...


In general regarding HPLIP:

HPLIP is developed by HP.

We (i.e. openSUSE) distribute HP's HPLIP software
but we do not develop it, cf.
https://en.opensuse.org/SDB:How_to_set-up_a_HP_printer

Issues with HPLIP are upstream issues that
should be reported directly to HP via
https://developers.hp.com/hp-linux-imaging-and-printing/support

The responsibility for this issue lies at HPLIP upstream.

Accordingly I close it as "upstream", cf.
https://bugzilla.opensuse.org/page.cgi?id=status_resolution_matrix.html
and "Background Information" in
https://en.opensuse.org/SDB:How_to_Report_a_Printing_Issue

Preferably post an URL to your upstream issue report
as reference here.