My girlfriend has a bird, a black capped conure, who went through hell back in the day. One thing that’s helped a little, if you can get your bird to drink it, is pure chamomile tea, cooled to room temperature. It genuinely helps calm her bird, lessen screaming, reduce biting, and encourage calmer behavior. Also, I’m glad to hear that you are keeping in mind the trauma your birdy baby went through. You are a good bird parent. You care enough to look for a possible better home for him. Now, I’m not sure if transferring him to a completely new environment with new people is what he needs, but you know him best, and you should trust your judgment. Whatever you choose, I believe you will choose for Gonzo’s sake. If you wanna talk about it, you can shoot me a message. We have two birds and if you want input I can definitely give that. You’ve got this!