I agree that #22236 should be resolved first.  As for resource guarding the 'wantobjects = 0' tests, do we really need to?  It takes a bit under 20 seconds to run all of the tkinter tests on this machine, and I don't think 40 seconds is an unduly long runtime for such a large set of tests, so I would vote for just loading both sets of tests every time.  Or if others feel the 'wantobjects' test should be guarded, I think we could just reuse the 'cpu' resource (since it's really just time that we're guarding).

And the rearrangement will of course be a separate issue; I only mentioned it here because that patch takes care of moving away from test_main and support.run_unittest, and may have an impact on how this issue can be resolved.