It is possible to add it via a remap. I did have a feature branch on the LinuxCNC github, but I delete it when the built-in version was incorporated into LinuxCNC mainline.
If you were to apply all the patches here in the right sequence you should end up with something that works.
sourceforge.net/p/emc/mailman/search/?q=G71Type2Remap
But why are you insisting on staying with 2.7.14 ?
