Setting BodySetup>Primitives at run time for DynamicMeshComponent

I have a DynamicMeshActor and therefore its root component is a DynamicMeshComponent. Its DynamicMesh is generated by taking a polygon and extruding via Append Simple Extrude Polygon, Append Revolve Polygon, etc. If I now take this DynamicMesh and feed it into SetDynamicMeshCollisionfromMesh pin FromDynamicMesh and DynamicMeshComponent to pin ToDynamicMeshComponent, it creates a collision mesh based on the Options fed to the node- basic shapes or convex hulls.

In the editor, selecting DynamicMeshComponent shows a section BodySetup and under that are Primitives which appears to be a structure holding Spheres, Boxes, Capsules, Convex Elements, … This struct is populated by the SetDynamicMeshCollisionfromMesh node.

My question is can I access this BodySetup>Primitives directly? I can generate my own set of primitives and assign them. Can I do this with Blueprints? If not, what is the minimum to expose so that I can construct the BodySetup>Primitives (most likely a series of boxes) and assign at runtime.

I have tried constructing a different DynamicMesh and used that for the pin FromDynamicMesh. However, it ignores my actual mesh even when constructed of simple disjoint boxes and constructs its own which is similar but more complicated (boxes overlap, have varying thicknesses, etc).

I got the second part working- in the GeometrySciptCollisionFromMeshOptions, select Oriented Box and uncheck Auto Detect Boxes. This will then construct a collision mesh identical to the disjoint boxes fed in. Joy.