Allow 'extend' button even when a user upgrade's cost & recurring details change. Does not allow the extend button to be used if recurring flag is changed
Fix recurring upgrades did not send expiry notices >24 hours before they where due to expire
Shorten various notification alerts
Improve scalability of notifying large number of users about expiring upgrades
Improve @NixFifity's Gift Upgrades integration. Titles for gifted upgrades/subscriptions are prefixed with "gifted" (editable phrase).
Add per-user upgrade "Exclude payment providers from notifications" option to skip user upgrades which have been purchased by the relevant payment provider.