The last open item under Backup & Server Status: which accounts get backed up on the automated scheduled run. Previously the answer was “all of them, always”, with no way to opt one out short of suspending it.
One column, one filter
The whole feature is a single flag on the account record, defaulting so that nothing changes for an account until an admin touches the new page. The scheduled run grows one more filter. The on-demand path, a single-account backup from either the admin or the account owner, never uses the flag, so a manual backup still works regardless. This is deliberate: excluding an account from the nightly run isn’t a statement about whether it should ever be backed up, just whether it needs to happen automatically tonight.
What shipped
A new admin page, Backup User Selection, sits next to Backup Settings. Every account is listed with a checkbox reflecting its current inclusion state, with one form and one save. This closes out Backup & Server Status.