Some of these things can be peeled off and kept on stable. Maybe the test changes should go on default, though I thought at one point test changes were OK for stable. This doesn't yet touch the actual building of the installer, which I was intending to put on stable because we effectively don't have one now for a modern macOS  (though PyPI installs seem to work fine). I'm wondering if we should just change the pyoxidizer config on mac to use the filesystem, like Windows. That might be too aggressive for stable (not sure if google uses this config).
Mostly I'm wondering if there's a way to fix the various help text problems, and also why i18n doesn't seem to apply (see the last 2 commits that show the remaining failures and also show the test changes made by an earlier commit in the stack). I'm not sure about the i18n stuff, but TortoiseHg also packs the help text into
hgext.__index__, so any fixes might help there too.