@chrisjsewell sorry for the ping, but I would like to know whether you will have a chance to take a look at this.

Thanks for getting this started. I'd also be interested in an improvement along these lines, but I'm not sure if it will work as such. Once you get the response from the proper authority, each will need a different doi_template to format the tooltip.

There are 12 DOI authorities in total, so even in the worst case scenario all of them would be possible to support. At a glance only CrossRef and DataCite seem to be relevant to our community. Multiple authorities can be supported either with a more complex template (hacky) or by changing the template API (which is why I asked in the PR).

Here's a complete monkey-patch supporting both authorities: https://github.com/quantum-tinkerer/pymablock/blob/main/docs/source/conf.py#L121-L216

That's nice! I hope one of the maintainers can find some time to get involved. (I'm in the same boat, i.e. cannot make it work with DOIs from multiple authorities.)