Hey,

I can't force the EBF to craft the hot enderium ingots, it will only produce stainless steel hot ingots. I might be missing something obvious but thanks for any help

You can lock the output hatch's inventory slot to only accept enderium hot ingots

How do I do that? I thought that might be the solution but I can't figure out how to do it.

The option in REI is greyed out

you can drag the item from REI to the slot to lock it

Amazing, thank you very much!