Just a small little annoyance Ive found in immersive engineering only playthroughs, getting slimeballs can be annoying if you dont live near a swamp and use a lot of sticky pistons.
I think a recipe should be added for the mixer called either industrial glue or bone glue etc, made with 2 bones and mixed in water. Recipe is inspired by glue made using animal sinew/collagen before the invention of rubber

The industrial glue could be used as a substitute of slimeballs except in the case of slime blocks,as well as being used in any future addition that would make sense to use glue.

I forgot the suggestion label how do I add it

Except that the mixer makes fluids, and the slimeball is an item. It can't very easily replace it in a recipe.

I have no idea if IE has the capacity to do this, but bare with me.

Bones, leather, rabbit hides were, and often still are, used to create animal glue IRL. Though processing of the materials would usually require an acid or alkaline treatment, this could be foregone for the sake of simplicity.

Of course, this still leaves the liquid to item issue. I have two ideas here:

1. The liquid requires bottling into Slime Bottle, that then must be crafted into a Slimeball, (leaving behind the bottle?) Or,

2. Buckets of Liquid Slime must be placed next to a block that generates heat and the liquid slime cures into a Slime Block.

Thoughts?

It's not a bad concept, I think it could definitely work, but I don't think IE is the mod to do it.

We don't even need slime for any of our recipes, so why would we have a recipe to make it? This is the same reasoning by which we don't have diamond in any mineral veins anymore, because IE has just no use for it. The mod is designed and balanced around itself, in order to always be a reasonable standalone experience.

Mods like Tinkers Construct or Inspirations (and maybe Create too?) are well suited for this sort of content, they aim for a much more vanilla-adjacent gameplay experience and actually make use of slime, so they would for sure benefit from this. IE doesn't really though.