Neither the wife or I ever had any kinds of reactions to any of thre critters. Usually if its handled by yur hands its safe as the hands have a good degree of skin thickness. Now if yu wereto slide it up along yur fleshy part of the under arm yu may get a different reaction. Lots of folks use gloves totouch corals, others do not.
What yu need to do before yu introduce that BTA is hold it i yuyr hand or in the bag an dhave a good long talk with it, and tellit "YOU" already decided where its able to setup housekeeping and it needs to stay where placed. LOL
BTA are the most catankerous critters. They wil setup and claim a spot dead smack on top of yuyr most prized corals. You goout of the way and move and rearraanbge it all to suit them, and low and behold the next dsay they moved somewhere else. It can be a challenge and it can also get old trying to outsmart the BTA. They can set in a spot for months and then decide its time to move to a new spot.......If it moves to a spot you do not like its easy though to get em loose by rolling up their stalk off the rock etc. or you can also cover that area with some cardboard etc to block out light and they will then decide "on their own" there is not enough light there to suit them. I have moved mine by blocking light and it works good. You can also use power heads to make it desireable or undesirebale locations as well.