Same answer as stefbeno, but I'm more for assemblies than parts within parts (even if a little better managed on PDM since 2020 if I don't make a mistake).
More generally, whether it is a PDM or a PLM, 1 reference = 1 file (or a batch of files) and not 1 file = n references
In this case, in your single room, you create the different configurations according to your different references. For each configuration, you can set custom properties for your different MEPs.
It all depends on how your PDM, models and data maps are set up. For our part, the configuration files are only on the library files (screws...) and on assemblies.
On the other hand, I don't see the problem with the ERP since there are already two codes for the different variants.