Here's what I'm assuming is the end-game you're picturing.

-All clients converge on this one DM standard over time

-Other standards effectively get weeded out, not to be seen again

-When someone on nostr says "send me a DM" it's always gets sent this one way, and this one way always works.

Or are you picturing there always being competing and non-interoperable DM standards? A sort of ice cream buffet, choose what you like?