i don't think thats a problem. if he doesn't like it he will get out of his tube and move to a better home.
i lost my featherduster for about 2 weeks. couldn't see him or nothing. come to find out he retreated deep into his tube, shed all of his feathers and was growning new ones. he still like the rock he is on and he is comming out now.
if the tube isn't attached to the rock, you might want to plant him straight up and down in the sand. i wish i did that to mine, but his tube won't come loose from the rock and i don't want to break it.