I think it is really important to find a way, to check the introductions and asknostr tag from time to time. And when someone sees new users reference them in a note or to quote their notes.

I also would not expect from new users to set a pow. So I really think that the proposal vrom nostr:nprofile1qqsyvrp9u6p0mfur9dfdru3d853tx9mdjuhkphxuxgfwmryja7zsvhqpzpmhxue69uhkummnw3ezumt0d5hszythwden5te0dehhxarj9emkjmn99ue6qm68 is one of the best balance. To only filter users, that got reported more often by you and your follows than whatever treshhold one sets.