Capping any level affects recruiting at all levels, because it’s an integrated ecosystem, and restricting recruits to their designated levels will have ripple effects. But I could go along with a D3 cap in theory IF that division was just basically completely lopped off from the rest of the game and made into a free to play, no credits sandbox (could also be used to test game engine tweaks, etc), an idea I’ve actually proposed a few times. But in that case, to preserve the functional market of D2 and D1 recruits, I think they need to turn up sim recruiting a little, because again, the game shouldn’t let the top teams of any division get away with lining up prime backups for basically free.
My primary concern is that it will hinder fluid competition at the D3 level. Capping is often presented as a way to help new D3 players, but it will hurt them the most, as it forces them to directly compete with the best teams in their division for the best players. Right now, new players can compete for exactly the same caliber talent that A+ D3 teams get - provided they know where to look. The problem isn’t the system, the problem is the lack of information about how it works (like knowing to actually select the higher level pools instead of D3 when scouting).
The resource-allocation aspect of the recruiting game is already straining the boundaries of college basketball recruiting gameplay. If we have to retain that aspect, the market has to be free and functional.