How to add new manuals to Info

This is a followup to How to change the INFOPATH, possibly only user wide? I’m asking this more general question because setting the INFOPATH doesn’t seem to be the only or the best way to add directories of manuals to Info.

More in detail, I would like to know how to make TeX Live 2019’s (the “vanilla” version, not the packaged one) manuals available to Info. The manuals are located in /usr/local/texlive/2019/texmf-dist/doc/info/.

A description of what I’ve tried so far is on my previous question linked above. (I think it would add clutter more than anything else, here.)