Describe the bug
Trying to limit Ars Nouveau mobs doesn't seem to be working.

To Reproduce
Steps to reproduce the behavior:

1. enable Custom Spawn Config
2. Add ars_nouveau:wilden_stalker for example to be restricted

Expected behavior
Limit any Ars Nouveau hostile mobs and not go over the max

Debugging
I looked through this and it doesn't seem to be outputting anything relevant to this.

Is the issue happening in combination with other mods? (If yes, please provide a full list)
I am on a All of the Mods 8 server if that helps?

Thanks for the report. In the past there were some issues with Ars Nouveau because some of their effects are using living entities and so they were wrongly "optimized".
For this reason all Ars Nouveau entities are excluded from the optimization per default to avoid such issues.

I will try to add a list of Ars Nouveau specific mobs, so that they are still optimized but in this case I need manually add a config for them which will take some time.

If this is something on your task list, you'll want to look at the new 'wilden' structures as their spawn rates are vastly different to the older versions of Ars.