Wow, lots of gitlab hate here but at thee same time lots of love. Everyone loves gitlab. I think the core issue is when things become so complicated, you can run your own git server. As I mentioned in another comment, projects like gitea are designed for complicated problems like this. If you are as savvy as you seem to be, spin up a VM and run gitea. A normal VM at digital ocean at $1k a month could handle any conceivable load. Don't 3rd party something you can do yourself for free.