Your reference to foot prison makes me want to remind you that there's no rule against wearing sandals (well, without socks).

If you have a pre-1780s attitude to tradition, most had no shoes. Post 1780s show up in a recent thread, check it out.

I wear Keen sandals most of the time, cooler weather have Doc boots, formal has Doc shoes (company has Docs on my safety boot allowance. Yes, kilt footwear is part of my benefit package.)