I have been. Hoping it cuts out some of the manual work and prevents me from accidentally writing a PR against an obsolete nixpkgs. The only changes I've made are ones I'd want to be upstreamed. So from the point of view of my individual devices, it's basically the same as just putting nixpkgs-weekly in my flake. I can nix flake update to pull changes into nix, and hard reset to update my local repo (which is now just an easier way to fast forward + rebase/cherry-pick).

We'll see how it goes. So far, it was broken upstream once when gcc was upgraded out of sync with godot3, and it looks like sublime-text might break next week do to an openssl change. But those are both artifacts of depending on weekly. If it stays this hairy, maybe I'll end up using the biannual release channels.