[abcdefg12]

And you have two or more servers serving this domain you’re out of luck

[lmz]

And this is different from DNS how exactly? The key and resulting cert still needs to be distributed among your servers no matter which method is used.

[cpach]

With dns-01, multiple servers could, independently of each other, fetch a certificate for the same set of hostnames. Not sure if it’s a good idea though.

[account42]

Not really, just forward .well-known/acme-challenge/* requests to a single server or otherwise make sure that the challenge responses are served from all instances.