Depending on how fast your anemone eats, you could try managing it by feeding the shrimp first on the other side of the tank. I have a skunk cleaner and a BTA and initially had the same problem, took a few days to train the shrimp that tongs on the other side of the tank = easy mysis, but I haven't had an issue since then. I feed him directly from the tongs and the shrimp takes several minutes to get through the mysis, during which I feed the BTA. The BTA is fast at eating, so by the time the shrimp wanders back over, its meal is digested enough that the shrimp doesn't seem interested in digging for it.