I get this spammed in the console:

(11:26:45) | Calling hook OnMaxStackable resulted in a conflict between the following plugins: StackSizeController - 2000 (Int32), ChestStackMultiplier (4000 (Int32))

(11:26:45) | Calling hook OnMaxStackable resulted in a conflict between the following plugins: StackSizeController - 2000 (Int32), ChestStackMultiplier (4000 (Int32))

(11:26:45) | Calling hook OnMaxStackable resulted in a conflict between the following plugins: StackSizeController - 2000 (Int32), ChestStackMultiplier (4000 (Int32))

Does not seem to  be a resolution
https://umod.org/community/stack-size-controller/46970-plugin-compatibility-with-other-plugin

I'm using v2.0.4 and it works just fine. https://umod.org/plugins/stack-size-controller#updates

But we can't use old versions of plugins forever.
It makes sense to run updated versions.
Would be good if your plugin worked with these too.

The conflict is with chest stack multiplier and does not seem to be resolved. I have no problem with StackSizeController and as for using old plugins some of mine have not been updated for many years and still work. You cant expect all plugins to work with every new plugin that comes out sometimes over 6-9 years. I still use a very old version of Quicksmelt (4.0.5) and have no problems with smelting and not burning meat  :).

This plugin does exactly what it's supposed to do. There is no conflicts with v2.0.4. You want this plugin - use v2.0.4