No change needed, you can use your current extensions π
No change needed, you can use your current extensions 



Extension Kit for Gunfighter Mk.IV
Meant for customers who wish to upgrade their existing Gunfighter Mk.III Tabletop variants with a grip extender."
Also, where does the black box go in the VKB Grip-to-Rhino chain?Same as before: GX12 connector to USB