I did an inplace upgrade of gitea to forgejo. No issues.
I've been self hosting this for 2 or 3 years now.
There has been zero maintenance other than the occasional update button
I use it for my docker compose files that portainer pulls from with the click of the button to update my containers when needed.
I edit the files in VS code with the git plugin and it works without issue
I haven't tried them but some people have made templates for obsidian
https://github.com/martinjo/obsidian-gym-log