I was looking at this
https://insteading.com/blog/keyhole-garden/ and thinking - the 3rd world ones look very cool, brilliant use of resources - so why not use 7 builders' bags in a square?
Then I saw photos #15 & #19 (from rich places - US mainly), which are nearly the same idea using good quality timber - but that's not rescuing high quality woven PP from landfill! What are they thinking? They're not even using pallets??
No. 19 also mentions soil compaction under the path - surely the path should be dug out to raise the beds and replaced with chopped twigs? Here I would use woodchip, but either way the path would gradually turn into a valuable source of humus - to be dug out and replaced with fresh woody stuff.
In a dry climate a 100% twig path might need to be laid with layers of mulch to keep the dry air out & moisture in.
I was thinking of adding a second row of builders bags to my current system of "compost and woodchip morphs into raised beds" but now I'm thinking of turning it into a double square keyhole which would have more bags with less pallets holding them up.
Cheers.