Feet not resting on the floor is uncomfortable and can be a risk factor for blood clots during long flights. I assume this can also be a problem for short legged passengers in the DA62.
My wife likes to ride in the back and we noted the same thing in our 2020 DA42. I cobbled together this footrest for her in the back seat of our plane. Left enough of a gap at the front for heated air to come through:
