@dick_turpin So now that I think about it, my whole thread was kind of nonsense. But when I said Vanishing Messages, I was thinking of some of the particular implementations from other apps like Wire, that some people like, and want fedi apps to add.
As I said in my conclusion, this is a lot of effort for minimal return, and IMNSHO we have much higher dev priorities (eg portable accounts, better moderation and opt-in search tools).