Hi Warr - and others - I have a tube/feather-worm that lives in a piece of rock that is covered by porites. This piece of rock is right next to my gorgonia coral. Now, I know that a gorgonia is not a LPS, but in theory the same principle apply.
I think that the tube-worm will most likely extend it's tube (build it up) to a point where it would be "past the point of irritation". I do not think that the coral would "burn" the tube/feather-worm, but, it might irritate it.....
Corals "sting"/"burn" other corals as they see other corals as invaders. I am nearly sure that feather-worms will not fall into this category.....