Yeah, doesn't the ACME bot defaults have it trying to renew the cert when it has like 30% of its life time left? Which means the CA would have to be down for Days/Weeks fo it to impact production.

Oh and you would definitely know about this outage because you would hear about it in your news, and the monitoring you already have set up to yell at you when you cert is about to retire (you already have that right? Right?). And you can STILL trivially switch to another CA that supports ACME.