I don't understand, u don't want to add breading in this game ( its a very good idea btw ) because its the philosophy of the PRO but u add this system instead who will kill the soul of PRO.
I think a majority of people prefer that u work on add ability + move instead of this system. And with a complete game u will have more players and more money.
Why not add a something like in 7g who max only 1 ivs to 31, but it must be a hard reward, like top 1 of the ladder at the end of the season. But u can't add this system to the coin shop, its pay to win, its like play lotto.
If u add this system that u will destroy the game imo, lot of players will leave.
If u want to add something that will encourage players to buy MS I recommend u to add an area only available for MS players, in this area the poke who spawn will change all months or 2 weaks if possible, but u need to add good poke inside, u can make a area with only cool water poke for exemple, then next time an other type.
Imagine a area where u can find only cool poke inside, and not really commun poke, all the players would like to go inside.
Anyway good luck and thanks for your work but please listen the community and don't do this system, u can add lot of things more interesting for the players.
Best regards.