Mixture of cleanup rules possible?

Hi!

Some months ago, I have configured our backup plan to delete old backups using retention rules.
Using retention rules, computers that have had a full destination drive were not shutting down probably. They got stucked showing the message "Operations in progress...".

I decided then to use "if there is insufficient space" as cleanup option. Now I have the problem that backups are written to the destination drive until its full. This behaviour was of course expected but isn't satisfying at all.

I would like to configure cleanup rules like the following:
Keep max. 3 weeks, retain backups if an incremental blocks the backup chain, but also delete if there is no space anymore on the destination disk so that users do not stuck with "Operations in progress..." when they want to reboot.

How can I achieve that goal?
Is there a workaround by using a specific combination of two or more backup plans?
I also wasnt able to find a dedicated "cleanup task" i could configure and distribute to my machines. This would be much appreciated as you could perform cleanups based on schedules.

Thanks for your help!
Regards,
Tom