Edit (and save) default Percussion Maps?

I’d like to make some modifications to some of the default percussion maps; as well as save my own to always have available with all new projects (without having to manually import it every time).

I have done this successfully with expression maps in the past using the DefaultLibraryEditions folder. But I poked around in that area and couldn’t find where default percussion maps are stored. Any ideas?

Could I get a confirmation if this is not possible?

In which case if it isn’t, I’d love to throw it in as a feature request. I have to alter the NP orchestral percussion map every single project for my needs; and would also like to have quick access to my custom maps for other instruments as I can for expression maps.