Ah, yeah, we were planning on using it and started integrating it but decided to shelve it until we could devote more development resources to it. It’ll probably require a coordinated, focused effort from multiple devs to make it happen. But if anyone wants to work on it I can at least join the discussions, and I agree with you: it would be a killer feature.
(For now, we went with CEL integration for request matching. Very lightweight, powerful, etc.)
I’d love to see Starlark modules for Caddy.