Thank you. :)
Just for the record, I have gotten and continue to get lots of advice from folks at Reef2Reef who are anemone experts, both planning the tank and dealing with this specimen. There are several threads in the anemone forum discussing it.
I’m not sure what you mean by mounted low. When the magnifica is on top of its planned rock island, the top of the anemone is in the upper third of the tank. That puts the par in the range that others at Reef2Reef keep them.
As to the location, it is as you describe, unable to touch any walls of the tank from the bommie top. The entire aquascape was planned with that design in mind. It has never left the bommie by touching the side walls and moving onto it. It leaves the bommie by detaching from the rock entirely and floating free. Same when it was on the glass at the tank top: it released.
I don’t think inadequate light is the issue that causes it to move. It has sometimes moved from higher to lower light, and did not move back.
While I do not know for sure, I suspect it has some foot problem that causes it to be unhappy with the grip it gets, regardless of the nature of the location or the nature of the surface.
Pics can be deceiving, but the last pic you updated it looks like it's only 7" or so above the sand surface. I thought in the past you have had trouble with it moving up to the overflow box?
I think the idea is for it to be unencumbered by not touching anything else in proximity...............kinda like king of the hill with arms spread wide.

It may be moving lower to get flow but then not getting enough(hi par encompassing) light. In other words it likes both and will keep moving until it's happy.
The tentacles look short...............they should be 2-3 times longer.
I'm just passing along info to help...............I'm not an expert but there are a lot of falsehoods about keeping these healthy. I don't know if the foot is damaged.......from the pic it looks ok.
I only have experience with Malus and they are almost the exact opposite in care when it comes to flow and light.
Like I mentioned I can get you in contact with my friend if you want to bounce some ideas off him.
He isn't on forums.
