Recently, NIP-26 has been back in the limelight in some discussions, because indeed a system of key rotation, and temporary delegation of event signing, is crucial in a mass adoption path.
Reflecting a little on NIP-26's critical points, I came up with a simple modification that seems interesting at first sight, although it would still require a mandatory flag:
https://github.com/nostr-protocol/nips/pull/1363/files

What do you think?
I ask this first of all to the NIP-26 haters nostr:npub180cvv07tjdrrgpa0j7j7tmnyl2yr6yr7l8j4s3evf6u64th6gkwsyjh6w6 and nostr:npub1l2vyh47mk2p0qlsku7hg0vn29faehy9hy34ygaclpn66ukqp3afqutajft, to nostr:npub1acg6thl5psv62405rljzkj8spesceyfz2c32udakc2ak0dmvfeyse9p35c who recently added back NIP-26 to Gossip, to nostr:npub1xtscya34g58tk0z605fvr788k263gsu6cy9x0mhnm87echrgufzsevkk5s, nostr:npub1hlq93jdtkfg29a8s7fqzzzh82q3pkc20rxucwt4geh6e56wk3y2qxdz5wg, nostr:npub1gnwpctdec0aa00hfy4lvadftu08ccs9677mr73h9ddv2zvw8fu9smmerrq and anyone else who seems interested in the issue. Feel free to tag others for visibility.