The original crafting combinator refills the assembler every time it scanns it. The forked combinator now only does this once when setting the recipe for the first time.
This breaks using a requester chest behind the crafting combinator as ingredients will only appear over time. This also means ingredients removed from the assembler at some earlier time are not put back into the assembler entirely as putting them back is limited to 2 cycles worth while removing can be more.
I was hoping upgrading to the forked combinators would fix the issue that the combinators chest would always overflow with time. But this just breaks half the setups I have.