I have a nice sized toadstool that I picked up and it had some xenia growing at the base of the rock. I just noticed today that the xenia is growing up the base of the toadstool. Any way the xenia will choke out the toadstool?
Try placing a small rock against the xenia to try to get it to grow onto it...but to answer your question, the xenia will grow away from the leather, so it won't choke it out.
Just cut the xenias away with a razor blade or a pair of scissors ... The leather and the xenias will heal up fine... The leather does look irritated by them..unless you just moved it that would explain why the polyps aren't extended