Good to hear it's looking better... I quarantine all of mine for a couple of weeks in an established 10-gallon tank with no fish before they go in the main display tank. All of them have exhibited interesting behavior during the first few days before they settle in, plus I don't think any of them ever took food for at least the first five days.
I think getting your first BTA is like having your first kid.... With the first one, you freak out at every little sneeze, but after you get some experience you just roll-with-it unless someone shows up broken.
Which brings me to something I can't tell from your pictures. If you have any powerheads in the tank I would strongly recommend you put a sponge on it/them permanently or at least until it stops moving around. Based on the white rock color around the bta, I'm assuming there is not a lot of light hitting that area which means it will likely move again once it starts to settle in. I've had one of my six manage to get in the powerhead twice and the sponge saved it both times. I guess some of them just like to wander around more than others. lol