As Debian now contains dehydrated as package and I trust Debian and hence the Debian Maintainers, this fork (to track changes on dehydrated) can be retired.
I stopped to follow the changes before ACMEv2 was in place, so this variant here stopped working with LetsEncrypt anyways.
However ..
.. in the Wiki there are some notes on how to use dehydrated on Debian Buster and above (and probably will keep this updated when I need to change something).
If there issues with what I write in the Wiki you still can open an issue here. Perhaps I listen.