In the process of wanting to use your Hetzner plugin with our systems, I've made a few changes that you might find interesting. They are separated out into three commits for clarity of what they add:
changes related to building the plugin as a snap as that is the suggested install method from the upstream certbot maintainers (perhaps they could be approached about publishing this plugin to the snap store along with the others)
the addition of one extra response exception which was used to debug the issue in point 3.
a fix for determining the correct zone to use that employs the helper function present in certbot. The existing method fails for two part ccTLDs, e.g. .co.uk, when multiple domains exist under the same one.
I have 0 experience with the snap store, but the other changes look pretty reasonable - especially the saner domain name guessing. I am trusting you with the snap scripts and gonna merge this PR.
In the process of wanting to use your Hetzner plugin with our systems, I've made a few changes that you might find interesting. They are separated out into three commits for clarity of what they add: