Pubky is indeed already designed with long-term coordination in mind.

Our open Semantic Social Graph method allows anyone to assemble any social graph view they want, and pull tag metadata from the sources.

To do p2p voting you need this and more, whereas using Nostr would be extremely problematic because there is no data provenance. You'd lose votes, have censored votes, have no way to seprate real from fake users.

Pubky, with PKDNS & SSG fixes that.

We are not actively working specifically on voting use cases any time soon though, so someone else would need to work on that if people want it sooner.