I’ve taken to making a little “10ft ruler” image that I use for dimensions (works doubly well for making ‘houses-etc’) but this would definitely be a game changer.
Ex - I’m currently working on a comic and have used a combo of the ruler pic I have and an image from some height comparison page online (can’t remember what off the top of my head) and it works well enough to keep proportions of characters and objects decent, but it would be so much easier to just enter it in. For instance, my five MCs are two men, two women, and a little girl. One of the men is more on the tall and lanky side while the other is average and stout. The one woman is slender but average and the other is quite petite. Proportioning these four to the child isn’t too difficult but I think a way to “measure” everything would be beneficial.