Also no, I emailed the dev who created it and he replied:

"multiAVCHD supports up to 32 audio tracks per title, but can only show 16 in the menu. The rest can be changed using the OSD of the player. Sadly this is a limitation of multiAVCHD that cannot be removed at the moment."

When I pushed him for more information he stated:

"multiAVCHD was aimed to be free for home use and for such use it is more than capable to produce content. Authoring menus for titles with 6-10 audio tracks or 7-12 subtitle tracks shows different goals and is out of multiAVCHD's scope. Anyway, the limitation cannot be lifted because of the way the SETUP pages are created. Since there is no free way to generate and properly mux IGS tracks (at least back in 2009-2010), multiAVCHD uses a small template with 16 button placeholders: 6 for audio, 7 for subtitles and 3 for navigation. There is no way to extend the number of the predefined placeholders/programmable buttons in this particular IGS."

Which is a shame :(