It is user friendly.
Server cost is only an issue if you don't value the community that much.
I think the primary thing is identifying the common denominator between socialists on here - in terms of what it is we equally/generally talk about. The answer may be anti-capitalist topics, news, history, /trash/, etc. This could be hosted on "one" (redundant) [b]main[/b] server. Then surrounding this you could make three-four different communities for the ideological differentiation, i.e. ML, leftcom, ancom, socdem, each with their own (redundant) servers. This would help develop theoretical understanding in the comrades, by letting threads on theory really allocate more high quality discussion, free from incessant shitflinging (which is the case on leftist unity chans thus-far).
I think something like this would take the community to another level. But it would require a common code-base / a wiki for making setup easier. Onion services would of course come with the territory, in line with the history of the protocol/community.
· Anti-capitalist (critique, news, etc.) + .onion
· Strategic (political ideology) + .onion
· Formal (gitlab/wiki/booru/archive) + .onion