I hear ya. These are just some of my very non expert thoughts... The bta is acclimating to a new environment. Your tank is not the exact same as where it was (every single tank is different, each being sort of like "earth-like" planets, but not exactly the same), hence the adjustment of zooxanthellae. If you move it, you reset the process and now it has to start acclimating again but it's currently not at 100% so that could be a detrimental step; or not. It will eventually get there imo but the timeline is unknown. I very much think all we can do in these situations is maintain water in acceptable ranges it will likely favor and observe. If it wasn't footed I'd say moving it was more of an option but it is and tbh doesn't look too bad to me (mine was pure white at one point). Light imo isn't as big of a factor as the nem will hide if it's getting too much (and has an appropriate space to do so), a behavior unique to anemone unlike corals which cannot move.. It is your animal however so the choice is ultimately yours.