What we’ve done before is simply eat into the shins. The shins are shorter when you wear heels. It works, but it’s not beautiful.
What I would do if I was after top realism, would be to create override animations for shoe kinds, that affect the ankle/foot/toe bones, and angle the ankle down. This could also affect the entire lower body if you want a more rolling gait when wearing heels.
I would then also have some offset on the character capsule to compensate for the feet sticking down further.
Or animate locomotion/height based on impacts with the actual skeleton, a knee/hip straightening torque, and some kind of constraints to avoid the character toppling over.
That unfortunately leads to foot sliding, unless you also fix it up with IK and “gluing” the feet to the ground. And even if you do that, you may end up with snapping when engaging/disengaging.