Okay, thanks! According to some help I got elsewhere, it looks like Corsair DIMMs will tell you what ICs they have based on the DIMM version number published on stickers pasted on the back of the DIMMS.

So ver 3.41 = B-Die

That means DDR4-3733 Vengeance LPX 8GBx2 and DDR4-3200 Vengeance LPX 16GBx2 kits have B-die.

DDR4-3466 8GBx2 is not.