The 1.1 DIMU mounts on the J1 and J2 headers. So if you are using some vectornav expansion board that mounts on J1 and J2, then you cant use the DIMU at the same time. Besides, I think that DIMU and VN100 is on the same SPI and possibly also shares interrupts.
But what you could do is to remove the analog IMU section on the V6 board and solder the Chip Carrier version of Vn100 in place of the AIMU. The pads around the V6 AIMU section is a direct match for VN100. That way you could still have an expansion board on J1 and J2.