BTA needs a solid deep cavity to place its foot. otherwise it will roam, and probably die. I have never seen ocellaris or percula in these anemones. They are preferred by GS Maroons.
I have 3 large anemones in 3 different tanks. In my 65 and 90g I have 2 ocellaris in each tank that is hosted by gbtas'. I have 2 tomato clowns in my other tank which is hosted by a gbta.
I got a new green bta yesterday too.....my clarkiis went to it in about 2 minutes. I have never seen anything like it. I have had those clowns for almost two years and the first minute they new where to go.