In the above clip, that is more a case of getting the plane to descend at normal freefall speeds and entering the plane.
I fly a very small parachute with additional lead weights to increase the max speed, so we are more at a glide ratio of 2:1 or thereabouts. This can be made to be flatter but the challenge is forward speed to match the a/c (and also operating at speed that wingsuiters can fly at)
Thought it would be close, it probably is just out of range of the PAC (and definitely out of range of a Caravan?)
Actually we have a very high degree of control and stability so formation work would be relatively easy if we can fly within the right flight parameters to make it viable. Going through prop wash or the burble of an a/c would not be fun though! hahaha