With this recent change:
Explosive Caltrops now does two additional “throws” of caltrops during the jump (3 total).
However, the second and third throws trigger an 18-second cooldown (rank 1’s cooldown), regardless of which rank you’re using. The initial cast will trigger a 18/16/14/12 cooldown like usual, but it’ll always jump back up to 18 seconds with the 2nd/3rd throws. I imagine the cooldown should only be triggered from the initial cast. Also, given that it’s triggering rank 1’s cooldown, the caltrops placed from the 2nd/3rd throws might be dealing rank 1’s damage.