The snap fit mechanism secures the battery very nicely. The solid base of the second design actually made the part more rigid and caused one of the snap fits to break when fitting the battery. You can see the difference in flex between the two designs quite clearly. Ultimately both parts will be more rigid when mounted, although leaving off one of the long edge screws will allow more room for flex. Due to the print orientation, the snap fit tower layers are horizontal making them weaker in the direction of flex. As it turns out, the holder was still functional with only one snap fit, presenting an unintended design optimisation in the event of any further iterations.