Only the in-world distances between the player and destination waystone are used to determine if "Short Travel is Free" is applicable. Add a check to see if the player and the destination waystone are in different dimensions and add a "Dimensional XP Cost" value. The default XP cost could be zero to preserve existing behavior but allow pack builders to set an additional cost for inter-dimensional teleportation.

Hey Blay, I'd love if you were able to take a look at this in the future. Would make for a nicer customization for modpacks. Thanks!