Can Lunging Spell Touch be used on allies?

The Lunging Spell Touch feat lets you extend the reach of touch spells. Can this feat also be used when casting touch spells on willing creatures? For example, can you lunge to cast cure light wounds on an ally?

The intent is clearly for enemy-targeted spells, as the feat description specifies that it’s used to "touch foes" and applies to "touch attacks", but I’m not aware of any actual mechanical distinction that prevents this from being applied to touching an ally. You should certainly be able to lunge and cast CLW offensively on an undead creature, so is it acceptable to do the same on a willing, living creature?