KiCad 7's PDF plotting is pretty awesome... depending on the reader you use.
@baldengineer seems to be a separate issue, JS is already partially implemented:
https://gitlab.freedesktop.org/poppler/poppler/-/issues/1421
(libpoppler is used by evince, okular and about all other PDF viewers)
@mmu_man This is why I am a hardware person. :)
@baldengineer wonder if it's possible with SVG as well… in theory you could use CSS in them, and have things shown o mouse hover…