@ricky89 Provided a great solution. It’s what I’ve done. I have a 500GB SSD removable drive I use for regular TimeShift backups for seven different systems. I’ve partitioned the drive with seven different partitions, one for each system. I just plug it into a system, TimeShift knows which partition it is set up to use for that system, and it just works. Pretty nifty.
Be aware, however, that SSD are not the best solution for long-term backup. They can die over time if not regularly connected to power. But for regular TimeShift backups (that get regularly replaced) an SSD works great.