There is a community edition but serious users will run into its limitations

No true Scot, then?

I’m running gitlab implementations at a few sites. I’ve not seen or heard of any performance limiter with a self-managed community edition that removes a tool the others still provide.

and it does not integrate neatly with external solutions.

Again, this sounds FUDdy. Which ‘external solutions’ are you using that a git-push fails on? Some spaghetti of saas tendrils seems to be already a risk, but I can’t think of any other external thing that it could mess up with.