Go to Envoy. Upgrade as soon as possible and enjoy constant movement up the seniority list from pilots flowing off the top. Apply wherever else you want to work and have a job at a legacy (American) in your back pocket if nothing else pans out.
Envoy will likely see some growth in the coming years as more flying is brought back “in house” to the AA wholly owned regionals away from contract regionals. The 20 Compass 175s aren’t going to stay there if that’s all they’re slated to fly for American. They’ll likely go to Envoy. And if Mesa and American agree to convert their CRJ900s to 65 seats (or not renew their flying at all) it would free up room in American’s scope to add 175s at Envoy. So growth is likely one way or the other.