If there are no other issues, then landing on the heel is also a non-issue. In this case, to force a change is "cookie cutter" coaching.
There's more truth to that statement that goes well beyond the question that you asked. In fact, ROGER gave you sincere advice that you can address other issues on.
With respect to your Heel - toe landing question, we all have different sensitivity "feelings" that allow us to engage, or not, perception and timing initiatives with muscle coordination, motor skills, and just plain ole .. "yeah, this is just about right!". On the other hand, some pitchers dictate a heel or toe landing simply because their movement - upright or compressed, forward motion kick starts an unsolicted response to land just that way.
Again, as ROGER pointed out... unless something is seriously wrong, leaving well enough alone is a coaching refinement/talent that is cultivated by experience .. not a text book "how to'.. one size fits all".