Little help with machine mod (locking inputs)

Hello guys ! 

I started MCreator a month ago and I love it, although I have some trouble with my mod based on automation. 

I want to make machines connected to each other with hoppers, pipes and so on, but locking input slots for hoppers won't come before MCreator version 2020.3

For those who don't know the problem : the extracting hopper will take both inputs and outputs from machines, which completely detroys any automation project. 

And then I thought : But they are plenty of machine mods out there ! How did they do it ? 

If you know some workaround this I'd love to hear about it ! 

Have a good day.