All providers should be "msog" or be upfront
You guys arent doing your research. I have had no problems once so ever finding ladies that allow MSOG once so ever. As a matter of fact the ones I see generally encourage it. If I do see one that doesnt offer it I know about it up front and I only book a half hour with them. It's not that hard.
If the provider has a P411, she can list activities down at the bottom of her profile. Otherwise, like others have said; check her reviews, check the FAQ or services on her website, and when all else fails...ask. Just be discrete.