Actually it seems to be pretty simple to build yourself a custom version of Plaits / Macro Oscillator 2 including the additional 8 models. Just download AudibleInstruments-2 and the newest eurorack-master as well as the updated version of stmlib from git and put everything together into one directory. I have removed all the other modules except plaits to make my life easier, and adapted the makefile as well. There are some very minor compiler issues but they can be fixed pretty easily. Just be careful when you add the context menu for the additional types, the 8 new types start from 0-7 and not after the other already available 16 models.
I have only hacked a simple solution together via the context menu, no button presses etc yet, but I will look into this in the next couple of days and if anybody is interested I can provide a Windows build for the Plaits module only. (different plugin so that it does not override your existing ones)
There seem to be some Python scripts which convert SYX files into a C++ file so that Plaits can use them. I am not sure though if one can use their own SYX files without rebuilding the module.