Hmm no that's even worse as then the server somehow has to handle both at the same time - I have no idea how the server could load both libraries concurrently without a heap of complication - and because they explicitly say 2.x client can't connect to 3.x servers etc then it'll all end badly very quickly.
Either you can create nodes that require 3.x and would thus only work with your fork of the server - and wait until we move and drop 2.x (March/April 21 - but maybe betas before then of course) - or you create 2.x versions that work with what we have today knowing you can bump forwards as soon as... - or you maintain both in parallel (one on say a 2.x.y branch and one called 3.x.y) so users can get both fairly easily. Or we look at dropping socket.io altogether (as indeed we aren't using many of it's features) - and just move to raw ws. (A not insignificant effort but...)
