I'm thinking no.
I wanted to ask if any of the DG experts on the forums have ever had experience with this?
I cannot imagine it would be.
Does anyone know if this is recommended?
If this is the case, then I have nothing to worry about here. Does that sound right to you?
I would consider RMAN Duplicate in which case you may avoid the shutdown.
b) monthly, shutdown this system and copy it to a 3rd site to host a separate set of business activity
All you have to do if DEFER the primary to the standby, then ENABLE and Data Guard will catch up.
resync the "mirror" with production