I will go with a 10-4 on that. Keep anything extra out of the inner workings.
You will add thickness and dirt and thereby friction where it is not supposed to be.
You can tape off areas that you don't want to coat. Also, modeling clay works great on the sights to mask off any tritium bulbs or colored inserts. I use electrical tape to mask off areas I don't want to spray. You can even insert a rag into a larger cavity to protect it.
FYI - Duracoat actually has a coating that is colored now and self lubricating just for intermal parts.