Context: https://mongodb.slack.com/archives/G0121N9LJ14/p1680641162332639

As a part of tiered device sync, I am trying to connect two clients to two different sync servers but using the same app id. The issue is that if I connect the first client to localhost:9090, and I explicitly set the URI for the second app to localhost:8080, the second client still connects to localhost:9090. From what I understand, this is because the app gets cached the first time and then the same app gets retrieved for the second client since the cache is built on app id: https://github.com/realm/realm-core/blob/063927de66f79a0afffbbe36c0bb14d27deba8f2/src/realm/object-store/sync/app.cpp#L185.

Not sure what a good solution here would be, but .NET E2E testing for tiered device sync is blocked on this.