Great idea using the chain as a plumb bob.
I belive the chain is also a measuring guide for how deep to set the post.
How are you liking your JCB? Seeing more kubota skid steers all of the time up here and less John Deere or Catepillar. Lots of Bobcat. My brother runs a bobcat on tracks. Seems like a good machine.
I really like the side door on the Jcb. I have had quite a bit of trouble with it; starter, alternator, egr and other little issues. I still think I would get another but a teleskid just because of the convenience of getting in and out.
👍for a good video love the wide open spaces and the good views