Custom Map Exports across multiple Model parts?

Not sure If I named the topic correctly, but think it will do..

Getting ready to export textures for a model.

Model is seperated in 5 individual IDed parts for painting individually.

Each part has 1 or 2 custom use channels assigned to them (user0 and User1)

When I am ready to export textures (UDIM / stacked textures per R+G+B / R+G+B+A), How do I make sure that each created User0 / 01 painted layer will goto the correct model part?

Will SP automatically know that the User0 and User01 created in Model Part01 will goto it?

and will do for each created User0 and User01 part?

I hope I explained this correctly?

Trying to not make this a TL/DR topic.

If you need more information / details, I'll be happy to respond with the needed intel.