Bug / Crash Material property changes don't work with ObiCloth

[timconkling]

(I'm not sure if this is a bug, or an unsupported feature, or if I'm doing something wrong!)

• We have a character in our game who wears a gown. The gown uses an Obi SkinnedCloth component for its cloth simulation.
  
• If the character takes damage, the gown becomes "bloodied".
  
• To do the bloody-gown effect, we're animating a property on its Material instance; a shader uses the property to do some color blending.
  

This all works properly when we use Unity cloth:

   

But when we use Obi cloth, changes to the gown Material's properties don't do anything:

   

(If we change the *master* Material's properties, we *can* get the bloody-gown effect to work with Obi - but of course, that means that all gowns share the "bloody" status.)

Why is this happening, and is there a way to solve it? Thanks!