In other words, doesn't the TurboFloat server first need to contact limelim's server to get the new custom field data in the first place?
Yes it does. And once it receives the new custom license fields (either by calling IsGenuineEx, or by manual re-activation from the customer) the new custom license field is only sent to the computers with leases once they renew their leases. So, if you have long lease times then that must be taken into account as well.
Make sense?
I guess the best practice would be to tell the customer to just restart the TFS server?
No, tell them to stop the server, re-activate, then start the server again.