[IslandReefer]

just my 2 cents worth.
rBTA's (at least mine) tend to move toward flow and light untill they reach the highest point....ie that rock pile. Also they like to have the stem in a crack or hole mostly out of the light with the top in the light.
For almost a year my rBTA stayed where I wanted it, but two days before I left for Calgary (holidays) it went walkabout....go figure....and I changed nothing...thought it might split.
Since rBTA's are not thinking animals they respond to eviromental and basic needs stimuli....ie sooo something made yours and mine move even if we can't figure it out.
I " direct" my rBTA using the logic above, by moving rocks into the places I don't want it to go and clearing a path the right way. I also use a J-cloth (clean,new rolled or folded) to keep it off corals and along the right path.....success about 50% good luck.