Interestingly, having accomplished my gross weight, forward C of G spins in the Caravan, it was then time for aft C of G sipns. The recovery was profoundly different, and has me thinking that it might be the spin recovery ability which defines the rear C of G limti for the Caravan.
Unlike the steep nose down dive recovery of the forward C of G spins, the aft C of G spin recoverys were pitch control full nose down, hold and wait with opposite rudder also applied. After a half turn and some pitch bobbing, the recovery seemed to begin. Indeed, it had recovered in the required one additonal turn, but it is weird holding the controls fully forward for that long, particularly in light of the vigorous dives of the preceding flights!
Though the control applications were the same for the two extreme spins, the length of time they were applied, and what happened next were very different!
That said, yes, 100 series Cessnas generally enter a spiral dive on their own, during most spin recoveries. Make sure you can quickly recognize the difference between the two, and can apply the correct recovery technique - because they are different!