You talk about distinctness and uniqueness. Yet your hard-locked male Viera would be a carbon copy of male Miqo'te.
Is your uniqueness argument that sincere?

Instead of hard-locking them to only mirror male Miqo'te why not allow the other side to also allow them to mirror a male Elezen in terms of height? There's nothing unique about making them short, male Miqo'te smiles and says hi to you.