I made my own out of pvc and large bike tires once. Designed it where it folded up. Put straps on it where you could tote it like a backpack.
I never used it and gave it away, but feel like it would of worked. I loaded my younguns on it and pulled them around in it once to test it out.
Like others said, especially where there’s plenty of trees, I’d think a single wheel would be easier to navigate obstacles.
