My guess is that if it was to be of actual concern, i.e. a potential hazard for anyone to be injured/killed, we would have known by now via some recommendation from manufacturers. Even though an engine at idle has some thrust, I'd think that a couple of seconds after you cut the fuel it'll be safe to walk either in front or behind the engine.
In any case, for the A320, our company SOP was to turn off beacon when N1<5%. This was removed from our SOPs some months ago with no further instruction on the matter