Oh that is what I did put Empower on Mesa 🙂
I dunno did I uderstand u, but u can add more than one infusion on configuration simply add ✔️ on the right.
Or maybe if u infuse in more that one config it will say infused in A,B,D for example.
Got those, it seems that they are rare spawn.
Just use ur Archwing with Tranq rifle and fly left and right near the edges of the map and they will spawn, max 3 those Avicheas can spawn, for me atleast.