As described in BluSunrize/ImmersiveEngineering#3206 :

Trying to add recipes to the Immersive Engineering Crusher with the same output (eg. output 4 minecraft:clay_ball from both minecraft:clay and minecraft:hardened_clay) will result in just having one of the recipes available.

According to malte0811 this is due to UniDict cleanup:

I looked at their code, they seem to be "cleaning up" the crusher recipes in a way that looks like it may well cause issues (e.g. assuming that 2 recipes are the same when a specific hash is the same.

Versions

Minecraft: 1.12.2
UniDict: 1.12.2-2.7b
WanionLib: 1.12.2-1.5
ImmersiveEngineering: 0.12-85

Example CraftTweaker recipes for testing:

mods.immersiveengineering.Crusher.addRecipe(<minecraft:clay_ball>*4, <minecraft:clay>, 3600);
mods.immersiveengineering.Crusher.addRecipe(<minecraft:clay_ball>*4, <minecraft:hardened_clay>, 4000);

hello, so, I added a config to disable the duplicate check & removal =P

A quick test with UniDict-1.12.2-2.8 with the same setup as I reported with looks to work perfectly.
Thanks for doing this so quickly!

Edit: I don't know much about the inner workings of this, so take this with a grain of salt, but it's working with the default setting of B:ieIntegrationDuplicateRemoval=true. As I read this shouldn't I be setting that to false to get around the problem? 😕

Either way, it works and I won't fuss about it.