doesn't seem like this is compatible, unsure due to not being able to understand how to put together every aspect of what i wish to achieve...
firstly i attempted to limit vanilla spawns to a maximum of 1 per player but still allow the spawners added by thaumcraft6 to spawn mobs, this was unsuccessful.
secondly i attempted to limit spawns for all mobs to the thaumcraft magical forest, eerie and eldritch biomes, this was unsuccessful.
limiting to Plains works fine as per the example, i thought perhaps the failure is due to me not knowing the correct input for the magical forest biome.. i have now tried 47 varieties and still no success.

also i would like to know that the champion mobs are still able to spawn when limiting spawns to skeletons and zombies, i have not a clue