I don't think this issue is related to soft logout, which is what happens when the user logs out of a device remotely. The issue I was running into was that the app, after 24 hours of being logged in, would get stuck in an initialization loop.
Sry, to be more precise, token invalidation has been properly handled in riotX as part of the soft logout feature;
Oh, awesome! I just installed Riot 0.9.9, so I'm going to test that out and see if the issue occurs. After that I'll switch to RiotX and check there as well and report any issues I find.