Definitely cool to see that I'm not the first person that crashed into this issue.
What this looks like to me though is that basically while haxdoc would definitely be the place to contribute and I'm happy to trust hax when they say this is all only moderate difficulty (it's how I interpret their second post) and just a matter of implementation, this also means that the only solution seems to be to first work on said docgen tool ? At least the wishlist and README of the project appear to point in that direction.