I only have a few minutes to comment (sorry!)
--Liking the size of Ionia's continent now - much better than before.
--The 'Serpentine River' issue is a real problem that I, and other lore fans, have wrestled with in the past. My solution was to have two serpentine rivers. (Which is something that happens in real life too - in the USA there are two rivers with the same name in the same state! Never mind on the same planet.)
-- Shurima is a decent size too. Good.
-- I'd look to the Freljord event map for a rough outline of that region. Pretty sure that's at least somewhat canon.
-- Bilgewater and Shadow Isles looking pretty good, relationshipwise too.
Probably cannot comment on anything else right now, but I didn't want to see you (and the other map/geography experts here) with nothing.
I swear something is in the works, but you know Riot. We can't give you a date because it might get pushed back etc. I know how infuriating it is, and I'm sorry.