Putting productivity modules into assembling machines that empty and fill barrels creates an infinite resource glitch that provides you with endless amounts of any fluid or gas that can be put in barrels. Any mod that adds more fluids in barrels is also affected which can quickly make any any resources infinite.

My request would be to make an option to disable productivity modules for all fill/empty barrel recipes since its quite the cheat especially in combination with the "more barrels" and "Acorn's module buff" mod.

That's not the case for this mod, perhaps you had some other mod causing the problem. The base game sets ignored_by_productivity for the fluid outputs of all unbarreling recipes, so when the mod enables productivity on those recipes, it actually has no effect at all.

Arguably I could submit a patch to the mod to cause this "issue," behind an option that's disabled by default. But as it stands, the mod doesn't do it.