That is funny. I was thinking I'd do something like that with the steel tracks I just replaced on my excavator. But then I decided that I wouldn't want to trip and fall on them.
I used the old belts from my J5 to form a mole barrier around my other garden. They aren't very wide and it turns out moles weren't my biggest enemy; it was jumping mice. Didn't even know those existed until I caught one on a sticky trap.
I had some old 29.5x29 tires i took off my 275b michigan loader,gave them to a friend who puts his hay in them to feed his draft horses. Cut the sidewalls out with a chainsaw they were only nylon belted.My friend at the scrapyard gets in rubber excavator tracks and makes pretty large raised beds with them.