I believe the additional paint slots were being tested but I’m not sure if they’re a work in progress or haven’t worked out.
X-Y-Z scaling was tested but did not work properly (fixtures sank into bodies or popped out of it).The way fixtures are now, regular ones scales X-Y, while some like mirrors scale uniformly on X-Y-Z to avoid distortion. As those fixtures stick out ofthe body, that scaling prevents the distortion of scaling on only two axes while the sinking/popping out isn’t an issue with these.