Well, some info came to light that it could be LWC causing this lag by handling hoppers incredibly inefficiently. The problem there is, LWC has not been officially updated since 1.8's release, and although Frost installed an unofficial version of LWC, our lag issues seem to persist - just less so than before. Info suggests that it's not open hoppers that are causing our lag after all, but the InventoryMoveItemEvent that sends items through hoppers to other containers.
This suggests we may want to instead start cutting down on hopper chains where possible, replacing them with water pushing the items across ice, but could also mean hopper clocks themselves are the laggiest hopper mechanisms currently possible.
This suggests we may want to instead start cutting down on hopper chains where possible, replacing them with water pushing the items across ice, but could also mean hopper clocks themselves are the laggiest hopper mechanisms currently possible.