Your description of the problem makes sense. If you think improving the user experience in this way is worthwhile, then go for it. Just remember, most users don't pay attention to the address bar.
For implementation, I suggest creating a new table, something like 'tb_user_category_index,' with userId as a foreign key and an integer that increments each time it's used. Automating this process in the database would be ideal: set it up once and let it run on its own, keeping things simple.
However, don't confuse this cosmetic index with a primary key. The primary key should only serve as a unique identifier for a record and hold no other information.
It should work that way. If you use the recommended Docker Compose scripts for immich, you'll notice that only a few volumes are mounted to store your data. These volumes don't include information about running instances. If you take snapshots of these volumes, back them up, remove the containers and volumes, then restore the data and rerun the Compose scripts, you should be right where you left off, without any remnants from previous processes. That's a pro of container process isolation