It also seems the author wrote this library specifically to be included in Home assistant (since HA only allows glue code to be included in the core and keep the implementation specific parts in dependencies) and does a lot of HA development. So he knew what he was getting into. It's not like he's library was added by someone else and he will now be overwhelmed by all the additional NixOS users. His requests to not repackage his code because of the support burden seems a little moot to me.