Link UVs of different parts of one object?

I know you can link UVs of different objects if they have the same geometry, but I’m looking for a way to link different parts of the same object. I pretty much want to have repeating parts of one object share UVs.
Up until now my process has been to manually separate the parts, link their UVs and than join them up again. I feel like there must be a better way to do this, as my current process is very time consuming and if I want to repack my UVs, they get separated again.
I guess I could keep the parts as separate objects and have them share a common parent, but that seems very counter intuitive and I’ll end up with hundreds if not thousands of objects.
Is there a way to do this that I’m missing? If not, do you know of an addon that has this functionality?

There might be a way of keeping them as separate objects ? Or use instances, or another duplication solution ? What’s your use case exactly ?

UVPackMaster - addon. Very good packer with keep overlaping function
I use TexTools to align similar UV islands. This is a free addon

I thought about keeping them all separate, but it would result in thousands of objects in my scene, so I don’t think that would be a good solution.

UVPackMaster definitely has the function that I’m looking for, thank you. Not sure if I’m ready to buy it just now as this seems like a one time problem for me, but I’ll definitely keep it in mind.