I could be being impatient this is true. Thanks for the post you could very well be right.A few friends got some berghias to try to cleanup their heavily infested tanks, a few observations from the group so far:
It takes a load of them to get faster results (still talking months here ) one 150 tank added 30 and it took 4-5 months to start seeing results. Tanknwas taken down a year later and many berghias were found while taking it down.
Another 150 gallon that added 6 took 6-7 months to start seeing result but they wiped out the aptasia in few weeks when he started getting results. He could see them on glass as aptasia became scarce.
One guy tried breeding them but it didn't work out maybe for reasons mentioned here. Believe they have a floating phase when they hatch so circulation /filtration in the breeding tank could be an issue. Yet some breeders sell eggs so should be straightforward to get them to hatch...
I saw a yellown cories wrass hovering over newly added berghias and not eat them. Not trying to over simplify things here but they are nudies in the end and I haven't seen wrasses, copperbands, bristle worms or stars .... exterminate a monti eating nudis population so not sure why they would for berghias. Maybe they do but its a low probability for them to eat all eggs or babies in a large tank with rocks and many berghias so few would escape and should growt the population same as for other nudis.