Oh god. That is Fillet Hell. I spent 30 minutes tackling it from many logical orders.
The worst of it is that you probably will need to manually trim the surfaces based on the rolled fillet “chutes” and then blend them with spheres as shown in: https://wiki.mcneel.com/rhino/foursrf
That however, is such a tedious process as to become it’s own kind of hell.
I would look into softening and sub-dividing the resultant .stl mesh in another software.
Also, you might try AppleMeshSoftening in the Windows version.
Automatic and accurate filleting (trimming) has always been a big weak point for Rhino, Windows included. Automation for something this complex may be better served by nPower, Power Solids…
But that’s $400 bucks and only Windows (noticing a pattern?)
Welcome to hell. : ) It’s nice a warm in all other respects here.
Also, you should consider using the TOOLING of the die maker to effect your fillets with Radiused mill bits and ballnose cutters. This can be programmed at CNC time, and exterior corners of a female mold can be softened by hand.
1/8th of an inch is so little, this can be done by hand, even could be vibrated (knocked down) with physical media. Just some thoughts.