Currently, the per player mob caps system implemented in Minecraft 1.18 allows for per-player mob caps, but the mob cap for each player is the same for all players.

I would like if there was a way to allow /spawn mobcaps to change the mob cap for specific players, while retaining default behavior for others. For example, you could have lower-level players get less hostile mobs (such as 30 at level 1) while higher-level players get more hostile mobs (such as 70 at level 30, 100 at level 100, and 200 at level 999).