Data center travel is currently garbage and BROKEN. The situation is not merely a matter of keeping servers from being overly congested, the system is broken. There's no way the intention was to allow a player to (1) start the character transfer process, (2) have the server they selected get flagged as congested after they start, (3) wait 30 minutes or more while the game times out and closes over and over, (4) and not be able to play on any other character whatsoever. Players are given no options once they are trapped in this situation.

I have not seen any official recognition by SE that the system is broken. So my guess is that we're gonna have this broken system for a long while and I'm advising all my friends to avoid data center travel particularly during peak hours. There's also ZERO chance that I will create a character on a low population server now and I'm advising potential new players on which low population servers to avoid starting on because who wants to get trapped on those?