I don't have experience with either of the above, but have been happy with the Velo Orange Porteur Double Kickstand on our tandem. I wouldn't trust it to a squirming kid, but I do routinely sit on the back of mine while it's on this stand. Not while riding, more that I often want to sit where I happen to store the bike.
https://velo-orange.com/products/por...uble-kickstand