sorry if im sounding offensive butI doubt that will happen. His KM is already nearly equal to FTG's speed. When he and the 9tails are gonna be pals, there is a possibility that he can be faster than with the FTG. Still, your theory is good though.
NOTHING is FASTER than TELEPORTATION xd
his speed in km is not nearly equal to FTG because FTG happens in an instant
with FTG you can teleport your ass in one second from earth to mars
with km you can NOT
and NO even if he cooperates with Kurama there is no possibility for him to be faster than FTG