Just start using HTTP 402 and JSON payloads. We can just converge on whatever ends up common; for me, there is already a monetary standard for the Internet.
I participated in these meetings for some time, during the rise (and rise) of Bitcoin. It's clear that the landscape of the financial web has shifted significantly at this point (for better or worse, in many ways), but standards, as usual, lag the market.
Earlier versions of Caddy were just a single binary that accepted signals to reload; the newer versions add a bunch of process management stuff that just got in the way of our existing tooling (...why remove the signals? ugh!) so we just switched back to Nginx.
The only signal we don't support anymore is USR1. (It's not a powerful-enough API for config reloads.) That was why you switched your entire web server stack?