When resourcing ongoing bookings, you can apply changes individually or to all future bookings within the series.
How to make changes to ongoing bookings
Go to bookings on the sidebar, then click ongoing on the top toolbar.
Select the ongoing booking and open it.
Select the booking you want to change from the ongoing booking list
Go to the resources and apply changes.
A box will open with all future bookings in the series.
Select "save for this booking only" or "save for this and future bookings."
Keyboard shortcuts
To prevent the dialogue box from appearing, before making changes to booking resources use keyboard shortcuts.
Save resource changes to only the current booking
Press & hold Alt / Option before making the change.
Save the resource changes to all future ongoing bookings in the series
Press & hold Shift before making the change.