Awesome!
I went into
EKAT and then selected Sawing > Sliding compound mitre saw > Accessories > Crown stop.
I noticed that the pricing was specified in Euros so I'm not sure if I somehow ended up on the European version of EKAT from before when I was messing with my country trying to find the manual for a tool that's not available in North America.
I've never personally ordered any spare parts, but I believe you can either ask your local Festool Dealer to order the parts for you or you can call Festool directly to order.