If you want to use bip32 to solve this problem, see this fork of this thread:

nostr:nevent1qqs8ax360qjvnrjmdy8sjkgc3s087nhfjzsscmflcvzl4ukmjmz3nvspzpmhxue69uhkummnw3ezumt0d5hsygxnp65cafj7j5ler2un76esafg7kv79qmu86j0kqzsnnthsp254zypsgqqqqqqs70pr7e

You would get a unique key for each client and could rotate keys anytime you want. For a proof of concept, the only things that should need implemented in the client are:

1. Cryptographically verifying a sub-account's identity, and

2. Auto-following new identities that pop up

That would demo the concept and then, if it gains traction, you could make the key generation more user friendly.