You can enable "Settings > Content > Avoid spam from unsafe relays (SpamSafe)".   And then you should go to your relays and turn on "SpamSafe" only for relays which you believe are filtering out spam.   Then you will be relying on the relays to solve this problem.

The side effect is that for relays that don't filter out spam, you won't get any spam, but you also won't get any messages from people you don't follow (Soon that will be a 2-degree web of trust, but right now it is just direct followers).


Right now the filter.rhai spam filtering script doesn't look up metadata, so the spam filtering script doesn't have any way to know the messages are coming from "Reply Guy", but maybe we can make some enhancements there.  Then you can filter these client side.