I'm sure a lot of the technologies on the list (like Yjs!) are well-designed and reliable, but I would not touch GUN with a ten foot pole. The code is absolutely inscrutable (what does any of this do? https://github.com/amark/gun/blob/master/lib/axe.js), the creator has failed to sufficiently explain any of the underlying mechanisms without complete hand-waving (what on earth is a "hypothetical amnesia machine" that supposedly underpins all of GUN? The creator has literally never given any kind of coherent explanation of it) -- it's just pure snake oil.