My 2 cents.. and others that are knowledgable may chime in.. I have found my experience that my mushrooms do better in a lower flow, without bending. That said, I will say they look better (to me) as they extend to the light. Does this say they are possibly reaching for light that they need?, and then possibly fail? Mine seem to be healthy and getting bigger. I have noticed that I had a few (mushrooms) in a basically "non-to-little" current area and they did not fair as well. I think everything needs current (and that is a relative term around here)..I try to avoid "bending" currents in any one direction for anything.
I think we always strive for the best spot (then again, moving anything too much, seems to cause an equal amount of stress, which can cause problems). I would try a spot for a week, if they don't look good..maybe a little move.
I have a bubble coral that was half in-half out of a current, it only attained good size bubbles after I moved it from the higher flow to a lower flow area (and lower light, ..lower in the tank).
Good size bubbles look good, but, the increase in bubble size is the corals way of expanding its area to take in light, was it a good move? Is it looking for more light? I don't know but it seems fine so far...
Make your moves causiously..slowly... I think if your shrooms move a bit it's no problem, thay can also pick stuff up in the current..
I do think that "some" things in high currents don't work well...
Good luck,
Billb