The topic you linked is doable, as some of the other people in the post have responded using such method. You do need to pay attention to permissions though, and I did do something similar recently whereby I had to repair a few permissions related with postgres or gitaly, but otherwise the majority of stuff worked. I have also restored a Gitlab installation using restic, of which I posted about here: 16.8.0 Backup/Restore Issues - how to repair? - #14 by iwalker this can potentially be a quicker method but again, permissions are some issues that need to be addressed.
The backup/restore procedures are probably the more easier and stress-free but as you found in your situation, when you have a lot of data to restore, it takes quite a lot of time.