Tried that and then just created a 3D Adaptive Clear that used “From Setup Stock” as the RM Source and … it wants to go all over the place vs just in the slot.
Just waking up, thanks @neilferreri.
I think was seeing bad results due to Stock to Leave being on, thanks!
And it looks like not matter how identical the models are/were F360 needs the containment boundary because of the way it interprets curves when they are created in 3D.