Chelsea Jaggi
Baking a displacement map should be possible by attaching 'Displacement' to 'Surface' for all materials, baking emit, and then finding/normalizing the euclidian distance for the three-channels per-pixel. 
by baking combined with base color and smoothness set to black (with scene background set to white and no spotlights) its possible to bake an ambient subsurface effect... by screening...
Instead of adding infinite variations on where to pack things per-engine, it would be nice if the packing could be completely arbitrary, with RGBA exposed per-result-image, and a drop-down for...