I may be wrong, but the OP's application is 4th axis indexing to get access for intensive 3D paths on organic shapes.
What I am not wrong about is that 4th axis simultaneous motion is a giant pain in the ass. Primarily because it is so very rare in practice that the tool sets for it suck; most work that would be 4th axis simultaneous goes to shops with full 5 axis machines. All the CAM guys are putting their efforts into full 5 axis tool sets and not bothering to circle back to 4th axis stuff.
Fusion is a prime example of that; Swarf has a 4th Axis Limit option that has been in beta for a long time, yet still doesn't work (it will spit out 5 axis motion). For the big project I'm on, we attempted to output 5 axis motion and manually delete the (minor) 5th axis motion, to no avail.
NX has great tools for 4 axis motion, but they rely heavily on geometry that has been explicitly created with this kind of tool path in mind. It is very easy to make what looks like basic 4th axis swarf geometry, only to find that the underlying structure of the surface is a spaghetti pile; all the multi-axis tools use the underlying surface structure to tell them where to point the tool, and if that underlying geometry is not *very* clean, the algorithms shit the bed.
Just to give you an idea of how challenging this sorta stuff is and why NX is such an absurdly good tool, this is how my NX reseller worked on our challenge (I would be the customer in his example, though he isn't using our geometry for this demo):
YouTube