roots slowly refill with sap. if you leave just 1 collector on each root for good and come back every few days you endlessly get 10 sap from each root. they never fully dry up. only temporaly. they slowly regain sap (slower than a single collector will collect sap) and thus the collector will keep going. moveing them is just faster to get sap.

but since youre bottlenecked by soft tissue way more than sap (i got like 500 sap now but not even close the amount of soft tissue) this has very limited use anyway. tough 10 sap is used for the new meta 25% stam regen for 5 minutes boot mead. so it never will be useless either.