Do you use 1 pulse per stack or 1 pulse per item mode? - I don't know if the 1st one is too laggy
Depends on usage. In a Factory (which produces many diffrent small Stacks) i use one Pulse per Item, while for things with a large Output (like swapping things from Overflowstorage to Sortingsystem) i use Pulse per Stack. Redstonepulses themselves are not causing Lag, only their Graphicupdates (what is no issue with Optifine) or the tings you pulse (The Retriever doesnt even Lag at all!)