I don’t know how tall the Heartland is, but I use the adjustable folding bench with my harps … but it is not quite high enough. To make it higher, I put a folded bath mat on top of the bench (with my velveteen cover over the whole thing). When I move, I put the folded bath mat between the bottom string and the column, near the base.
To move the harp and bench at the same time, I use a length of rope that is tied into a circle. I put one end on the bench legs and the other over the top of the harp.