Stack Modifier Incompatibility

Seems after recent updates, the stack multiplier option in the config for this is no longer compatible with StackModifier by @Khan
Not sure what the issue is, but unloading StackModifier results in the stack multiplier option working correctly. There are no errors or logs in console to report, so I've tagged Khan here in case there's something under the hood that needs to be resolved.
 

So the paid version of Stack Modifier still conflicts with TCLevels.
I've swapped to the free version on UMOD and it's all fixed now, I'd recommend if anyone is using this plugin and needs the two concepts to work together, to do the same.