I have moved my muffler to get the tire off and it wasn't a big deal . I guess if you got a lot of flat tires it would be of concern or if you were doing endurance racing and had a pit crew. A little easier then taking it all the way off. Not moving it would be better. How many flats are you expecting?
When I was in high school I worked in a tire shop, the record for flat tires, for one car in a day, was three. (that I saw) Funny, it was a Jaguar and it had knock off hubs. It would seem like knock off hubs would make changing the tires faster, but, the splines were always so dirty and corroded (New England weather) that it was always a battle to get the wheels off. Oh, and then the spokes, these wheels invariably had, were usually loose. Sorry for the digression.