In any case that wasn't my point earlier. That was that I never had the issue on IRC that my homeserver somehow got stuck for several minutes while it did "something" in the room resolution protocol before suddenly catching up all of a sudden. And that I'll take netsplits any day over it being stuck.
I've never experienced what you're describing with the homeserver getting stuck while it did something, though I have had Element Android time out and seemingly not notice for a while & keep spinning, but that was the client's fault, not the server. My best guess is that whatever you experienced did get fixed!
Not sure what the issue was in the end, but I have had it with all clients I had tried (mobile, desktop, ..).
In Matrix it could be a problem, but practically it's not a problem even in the largest room #matrix:matrix.org with probably thousands of servers. But it makes joining that room quite slow and resource intensive.
Of course there is no IRC network with thousands of servers, because accepted hosts are well curated by the rules of the IRC network whereas any Matrix server can join the global federation. Granted, you don't need to join a chat network with an IRC server, but then neither does a Matrix server.
Sorry you had that issue!