"implicitclass" causes user-specified print settings in GTK applications to be silently overriden/ignored

I reported an issue in the GNOME/GTK forums related to a serious basic network printing problem involving CUPS, where printing from any GTK application would result in overriding of user-specified print settings (either the system settings would silently override the user-specified settings—like duplex-vs-simplex or color-vs-monochrome printing—or other unexpected and seemingly random things would occur, like printing on massive-sized paper when that is not specified anywhere).

I tracked it down to be related to implicitclasses in the CUPS protocol.

Could you please work with the GTK people to resolve this issue (or else help to determine if it just needs to be addressed on one side vs the other)? I've tried disabling ImplicitClasses in cupsd.conf, but it doesn't seem to help.

Here is the issue as I reported it in GNOME GitLab: https://gitlab.gnome.org/GNOME/gnome-control-center/-/issues/2463

Thank you in advance. It is a serious problem for network printing and does not help in efforts to make Enterprise Linux Desktop viable and reputable.

No source files, tests, or entry points are named. Start by reviewing the linked GNOME issue and the implicitclasses behavior in cups-browsed, then reproduce printing from a GTK application; done means the responsible component is identified and user-selected print settings are preserved.