You can use Caddyfile snippets to copy repeated config to each site block:
There’s no way currently to set configure propagation checks globally, but noted, we might add a global option for that at some point.
IMO, the propagation checks in general were a mistake to add. But we’re still collecting evidence of whether it makes sense to turn off by default or remove altogether. I think a configurable delay is useful when it’s known that the DNS provider is slow, but maybe the DNS lookups are possibly not as important to have.
In a sense, the point of propagation checks is to avoid having ACME issuers waste cycles doing a lookup for the DNS TXT record if Caddy knows it’s probably not ready. That way it offloads the processing cycles to Caddy instead of the ACME issuer. Since it’s a free service, trying to not add additional wasted pressure to those services is ideal. But on the other hand, DNS lookups are pretty cheap. So I dunno.