Data point on limits:
Friday, 10/16, one BB card
Kate: 3x$500, 1x499.99 = 1,999.99
Customer Service Register: $500
Total: $2499.99
So not sure about new limits or what it means, but this has been my MO for a very long time with this single BB. Cannot speak for trying a second one right afterwards and if 10 minutes still works for Kate.
Cheers,
PedroNY