Sure, but does it not help at all? What's wrong with having multiple layers of spam blocking? It doesn't have to be effective, just not useless. Even removing 30% of the worst spam is better than not. And this is much more relevant to bitchat than amethyst.

Spammers are scripts running on desktops, sometimes with GPUs, wired to a power outlet. There is no way battery-based systems can beat them. All you are going to do is to waste people's batteries. We implemented pow on amethyst, but it was clearly draining way faster than what we though it would.