So lets say we have a subdivided cube and then in the vertex shader its positions gets normalized turning it into a sphere of a certain displacement value (a cubeSphere).
The cubeSphere is originally 1 unit so the physics engine when adding a sphere Imposter makes it always at one unit. Sense I know my displacement amounts I am hoping to update the radius of the bounding sphere to match. I might figure it out here, but if anyone has done this before that would be nice to know.
Solved
?._physicsBody.shapes[id].boundingSphereRadius = #
?._physicsBody.shapes[id].radius = #
(Wingy waves and then looks over P8’s shoulder to see what mad scientist experiment he is doing.) 
A little note: We have seen the BJS PhysicsImpostor.updateScaling() [something like that] … cause a physics missed-collision fall-thru. For example… if a sphere is on the ground, and then you up-scale its impostor size, it COULD fall thru the floor. A sneaky way to fix… is to apply up-Y-axis linear motion (impulse, force, etc) so the sphere is actually flying when the up-scale happens.
Fun! Likely off-topic. Note… that updateScaling() or whatever it is… wherever it is… (plugin or impostor class)… that thing does a “delete old impostor, add new one” action… to do its update, I think. FYI. Hope you’re doon well.
do you have a controller you can plug in? If so Ill share the scene with you if you promise not to tell or show anyone yet 
Thx for the offer, but no controllers here… other than the landlord and price tags on survival supplies.