NIP-42 is not theoretical or conceptual, it’s a merged NIP with a spec. It’s not speculation for me to say what it enables.
We’ve already built NIP-42 optionally in to one of our relays and it works on Coracle, the only client that I know of that has a working NIP-42 implementation.
Nobody is able to put any of these features in to practice unless some critical mass of clients support it. I’m not trying to get “every” client to implement it, I’m trying to get the most popular clients to implement it so that it can be used on the network.