about if the jib track had a smaller radius than the sweep of the jib?
First the use of the describtion of SWEEP of the jib. This is always smaller than the foot of the jib sail !
Secondly, this would do something you want. Open up the leech with increasing winds or when going on a LONG reach. On short reaches you just slack the jib sheet a bit and forget about that 1 or 2 seconds low of speed.
Wouter