Currently, if you cancel the balance payment (to update it with extras/amendments), you lose the option to send a new balance payment link for the new amount. So the system is currently disjointed because there is no easy way to record amendments and take payments. This is a problem as when you have busy check in days with 60 or 70 groups coming in, all the info needs to be on the check-in reports which isn't if amendments are made and there is no way of seeing if amendments have been paid for.

Case: https://pitchup.my.salesforce.com/500P100000Qf78L
Slack: https://pitchup.slack.com/archives/CG802BWGJ/p1747216945105179