Should multiple displays be a release-blocking criterion? I can imagine
a desire to ship a new release on-schedule because of significant,
content that works fine, but with multiple display support deferred for
an update because upstream problems are likely to take a while to fix. I
am uncomfortable with the notion that a release must wait for all
desktops to work with multiple displays on erery architecture. It is
desirable, yes, but this sounds like a QA attempt to control development.
Your criterion should be limited to hardware that works in single display
configurations.
I think two displays is a reasonable limitation. Even with that, test
coverage will be extremely sparse - there are just too many devices to
make tests of different combinations practical. (If we cannot test it,
we should not claim a release meets a criterion.)
If I can install three graphics adapters in a machine, and each supports
four displays, would you require that I can run 12 displays on each
desktop? Lovely if it works, but too rare a use case to be a blocker, or
even to test on a regular basis.
Slots capable of driving a graphics adapter are very limited, but what
about USB devices? With a few hubs, I could connect scores of displays,
and your criterion asserts they will work.