Indeed, design for CNC and 3D printing is also my primary use case :)
Plasticity being based on Parasolid, the 3D kernel of NX, which is a top tier CAD/CAM for manufacturing solution with a very solid 3D constraints implementation in "synchronous direct modeling" mode could probably be extended into that direction (not sure which part of synchronous mode constraints is actually part of the 3D kernel and which part is exclusive to NX and SolidEdge). But perhaps there are some non-competition clauses in place with which Siemens ensures that 3rd party developers cannot use Parasolid to develop a 200€/seat NX competitor any time soon?
In that case 3d constraints could be an interesting direction for MoI on a path on which Plasticity might not be able to follow for contractual reasons. (This is all hypothetical and mainly based on my puzzlement why they haven't implemented this so-important feature from the beginning already when it is potentially all there in the kernel? But no clue, perhaps all that is not in the kernel and would be a major effort. Or 3d constraints are simply something they decisively decided against for whatever reason).
I just think it could be tremendously helpful and enable more people to use the programs in scenarios that are relevant to them.