Source list revelance by Document type

Dear experts...

I need to create STO's to move material from between storage locations within the same plant.

For this we have created a different document type, similar to UB.

The problem is that the source list requirement pops up, since it's set at material master level.

We're trying to avoid having to maintain the current source lists only to add the origin plant, as this will put additional burden on the master data team moving forward.

Is there any configuration setting that would allow to bypass the source list relevance by document type? Are there any user exits in ME21N that would allow to bypass that error?

Thanks