hmmm the whole point of prestige icons is that you "earned" them so maybe you can toggle every icon below the prestige you currently have or make it so after p9 you can toggle icons however you wish (I assume that's easier to implement)
covert adder
hmmm the whole point of prestige icons is that you "earned" them so maybe you can toggle every icon below the prestige you currently have or make it so after p9 you can toggle icons however you wish (I assume that's easier to implement)
hollow quail
Yesss, maybe after we get all of them or like you said the below ones 
cerulean wigeon
yeagh flex that p6 and p9 pets the way you want it 