I do not expect SN to run a mint. Instead I'd imagine SN to designate the list of, say, 10 mints that it accepts nuts from as payments for posts and comments. The users zap each other via DMs instead.

The principal difficulty is that the user side software must unencrypt all the messages, connect to all the mints it wants to connect and reissue all ecash. This is far from ideal.

What might be better is if somebody not from US hosted a clone of Liquid with 100-1000 times less fees. The code is already there.