support for alternative models

[realCallMeJ]

while trying to add a drawable that is an alternative model, whether it's through opening an addon or directly adding a ydd, it says the drawable was added, but nothing actually gets added to the drawables list

[grzybeek]

hey, currently there is no support for alternate models, because it would require to generate pedalternatevariations.meta file.
It is planned somewhere in the future for sure