Every single modifier in the homebrew builder is there only because it is used in an official capacity somehow. There has never been an official feature that grants a choice between these three stats, and that is actually selected in this manner (using a modifier). The four non-UA feats with this option—Fey Touched, Shadow Touched, Telekinetic, and Telepathic—all present in character builder/sheet feat selection as separate feats, one for each ability score (INT, WIS, and CHA). This is due to the feat spells needing to be keyed into using the selected ability score.