My pair of Oscellaris Clownfish have been hosting my Torch coral for about 4 months now without any major problems. A few weeks ago my Frogspawn and Torch weren't looking good, but this was about the same time a sea hare went missing. My LPS look good now though.
I know this probably isn't helpful for you, but my LPS don't seem to mind the clown. The first few days they shut and barely showed any flesh but after awhile they fully opened again and have been doing fine. Even when my clowns are a bit rough the torch stays fully open.
I'd imagine something similar would happen with soft corals. I've seen lots of photos of clowns hosting leathers and people don't seem to report problems.