In case anyone is interested:
I spoke with ruddercraft and they confirmed that the high performance rudder (https://store.ruddercraft.com/index.php?route=product/product&path=181_29&product_id=135) is 24" and is the same as the longer 48" rudder (https://store.ruddercraft.com/index.php?route=product/product&path=181_29&product_id=136) that comes with the kickup kit.
They confirmed they you are ok to cut down the rudder "a bit" without loss of performance. I cut 13" off of mine and noticed no difference in steering even at low speeds (less than 1 kt). I also cut it at an angle so it should do better with kicking up. I'm still around 3" deeper than the keel and will most likely cut it down further this winter when the boat is out of the water.
The reason for doing this is outlined in the below post which basically says that the high aspect rudder basically negates the fact that you have a shoal keel.
https://thewakesileave.wordpress.com/2020/07/21/additional-minimum-draft-when-the-rudder-is-down/