I was confused why my laptop dropped 20% battery within the span of 5 minutes or so, and realized it was because btrfs-dedup@var-home.service was using a ton of CPU. Would it be possible for this service to be setup to pause when running on battery + only run when the laptop is plugged in to avoid situations like this?
On my own portable system I just disabled the task that starts this service, because I’ve got plenty of space and the dedupe service was slowing down games when running at reduced power limits to extend battery life.
I do think what you suggested would be a more useful default for portable systems though.