dupe glitch how to:

1. place blueprint
2. add items to storage bin
3. when belt is full or bin is empty, delete bin, merger and the little belt connecting them (when the merger is removed the big belt loop is made one entity with no beginning or end wich doubles the items on the belt).
4. delete the big belt (and you have double the items on the belt)
5. repeat ad nauseam

Credit to: gamebuster800 on YT for showing off this glitch.