Well, it certainly saves a little time wasted on lifting the car and removing the undertray, but the bumper doesn't affect things much for the pulley install. What would make the pulley install easier would be removing your radiator + core support, but unless you already had plans to upgrade your radiator, it's kinda overkill
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Other than the tricksy bit of actually getting the crankshaft bolt loosened the first time, the pulley install is really simple with the right tools in hand.