Normally the weight NBT tag prevents fish from stacking. The system is mostly aesthetic providing players with a little randomizer to catching fish but for some it might just be seen as inconvenient.

A toggleable config to disable it would be nice.

Might conflict with later plans (Advancements, Aquariums, Mounted Fish, etc.) that would use a weight system to determine size, but we can just use a default if they're disabled.

Added in f72a21d