1. generate new key (I kinda wanna do a BIP-85 style derivation, but I would need the main private key for this)

2. create a replaceable event with this key (no link to your main key); content is encrypted with this key

3. store key and replaceable event naddr on a tagged self-DM

if you want to share/collaborate with someone on this particular note, you can reveal the key with no implications to your main key