Salut!
Is there any chance of a phantomface that uses block offsets rather than absolute world coordinates? (Think of command blocks, and their use of '~' to indicate the position of the current block/player the command is being executed from.) It would make for some interesting inter-mod interactions with Funky Locomotion, whereas right now, a phantomface will remain bound to the same block after moving.

This however, probably shouldn't be incorporated with the default phantomface because of the possible security issues with protected blocks/areas. Instead, it should be a separate block/upgrade that is server-admin disableable via configs.