Presentation of grob descriptions in the Internals
In the Internals Reference, the individual page of every grob (for example, https://lilypond.org/doc/v2.23/Documentation/internals/notehead) lists all properties for which the grob definition has a default. To find other supported properties, one has to open new tabs for all supported interfaces. This was repeatedly reported cumbersome.
At https://lists.gnu.org/archive/html/lilypond-user/2021-11/msg00193.html, there is a discussion with some ideas as to how this could be improved.