Plate Leveling

I need to attach 12 X 24 fixture plates to my table frame and have the correct quantity of plate leveling fastener studs (SKU: F5-PLF001-BDK). I see a 12 X 24 mounting kit (SKU: F5-PLT2412-Mount-K1) is now available. Did I screw up and buy the wrong mounting pieces?

That is the correct kit. Only 4 bolts are needed.

So, I ended up with the wrong mounting bolts.
It looks like I will need the hold down bushings for 24x12 plates to make this work.
Are those bushings available for purchase separate from the mounting kit?