I'm not enthusiastic anymore about championing my patches, knowing I can always maintain a local patchset or submit them to Proton
It's no use sending them to Proton because the same people who maintain Wine and Wine Staging also maintain Proton. You could try to get the patches accepted in another Wine derivative, but I think a bigger problem may be that the infinite-sleep workaround kind of only works by accident, so even though it works for the current version of MS Office, I expect that it will break in a future version. I hate to say it, but your time and energy, which I greatly appreciate, would probably be better spent on other Wine bugs.