Does not actually work

[LokeYourC3PH]

Alright, so, as you can see from my screenshot below, I set the limit to 8 just to test.

However, as you see from the image below that one, there are far more Acolytes visible than just 8, decreasing my FPS.

Any idea on why the mod doesn't actually work as intended?

[Discusser]

You probably need to click on "Apply max entity count globally". However if you want to limit entity count, I highly recommend you do it only for the entities you want to limit.
Also note that by default, pressing O toggles the mod, so check if it's not disabled via that keybinding.