Well, the answer is certainly not 6:30 pm EDT. I got someone with a pretty strong language barrier. Took 20 min to do ..... a seat change. The person had to ask permission (or instructions) to move me across the aisle. Not in/out of E+, not an upgrade, a seat change.
This has been my experience EVERY time I've gotten an overseas center. Then I got a domestic center and was able to change routings, upgrade with miles, etc., all very easily.
Anyone keen on how to get the domestic help instead of overseas?