I have now – at least temporarily – disabled mob limits. Instead I have added a layer where one can see on the map all the player-controlled mobs. You have to switch that on on the layer icon so you can see them.
I hope to get a bit more transparency of the mobs being loaded even though players are not there etc. I hope to get a deeper understanding of the server load through this. Please note that this feature is only for me to be able to debug and will disappear sooner or later.