My goal is to be able to lock the top hopper by powering it with redstone. But however I seem to go about this, it seems to power the dropper, sometimes only when it receives a redstone update.
The rules of quasi-connectivity are that "anything that can power a redstone component above your dropper can power the dropper itself, even if the redstone component isn't there."
This means that any way of directly powering the hopper will indirectly power the dropper, and there is no way to lock the hopper without powering the dropper.
Is there a way to lock the top hopper without powering the dropper?