Sorry Casalt, you will find a lot of things in this hobby are based on opions, varied experiences, speculations, and theory.
While Ed may have had these stars eat his zoas, that shows a potintial for them to do so, not that they will.
Where as a zoa eating nudibranch...will eat your zoas, not ifs and or buts.
You will find these debates going on about a lot of hitchhikers, crabs. shrimp, stars, nudis, sponges, etc....
So things are black and white, some fall in a grey area. I think this star falls in that grey area, while only a few people I have ever seen mention problems with these stars, there obviously is the potintial for them to be a problem, it maybe a 70/30 chance, but now it falls on you to decide if you want to take the risk.
I would not suggest feeding it to your BTA but rather just take him out of the tank. You can try the shrimp, but from what I read above, it isn't worth the hassle, perhaps there is a wrasse that might pick them off?