I’m ok with players being fair game if they’re out of their crease when the ball is in play. This one, in itself, looks a bit scummy.. he wasn’t trying to gain an advantage (not like batsmen starting their run early and then crying when they get Mankad’d). If his other wandering was the same kind of thing… just going for a stroll before the ball is officially dead… I’d definitely call it unsportsmanlike, and wouldn’t want my team to do it.
But if my team did it to tilt an Ashes test in their favour, I’d get over it. Rules is rules, innit.