Harvesting creates a new seed virtually every time. I don't think it should occur that often. I suspect the first seed should be deleted (ie used to replant), and any additional seeds should be kept as harvest results.

This mod is designed as a development of vanilla's automatic harvesting mechanism (water flow, piston). There is no plan to give dispensers a stronger ability than current.
Sorting and deleting harvest items is a new feature and it is the OP that does this with this mod. It is recommended that you use the higher cost other mod machines or make that yourself.

Supplement:
Vanilla items have no way of identifying that they are "seeds" or "crops". There is no exact way to exclude only "seeds" from the block's drop list.

Ah, so this is actually how shears work on crops. Thanks for clearing that up.