It's been a bit since I really read up, but silversides were linked with quite a few nem deaths. The conclusion was that as a not for human consumption product, the fish aren't treated with food safety in mind and carry some risk of being spoiled before freezing. I also read that gut examination of anemones showed that they almost exclusively feed on planktonic foods. These two bits of info are the main drivers behind my choice to not feed them anything large. My BTA's might get an occasional squirt of thawed LRS or Reef Roids, but essentially just get whatever floats by in the water.