The same assumption was already fixed once on the dashboard side: https://github.com/vatesfr/xen-orchestra/pull/9997 counts sequence schedules in the backup computation, merged back in June.
So the home filter looks like that same fix never made it across, which is a better argument than "it would be nice".
On your second point, XO 6 may already have part of it: there's a Backed up VMs tab that lists from what's actually on the remotes rather than from the job config, which is the "like the restore page does" bit you were after, and https://github.com/vatesfr/xen-orchestra/pull/10277 is an open fix for a caching bug in it.
I haven't used that tab myself, and since it's built around VMs that do have backups, I don't know if it gives you the negative view you want. If it doesn't, https://feedback.vates.tech is where that gets counted.