I'm not sure how anyone could walk 5+ miles a shift @350lbs and not injure themself, unless they were that big from training for Strongman or the like. Humans are not meant to have that much fat.
Well into obese (but less than 300) and it’s really not an issue at all — walking is a very light activity (and far easier than standing). Also notably, this habit has not lead to any weight-loss, or perhaps I eat to make up for it.
Ask me to run however and I’m dying in short order.