The whole frame failure idea with aluminum is what kept me from purchasing a Swift. I would have to get a steel frame regardless. Manufacturing tolerances are fairly broad when it comes to seat posts in my experience. The I.D. of the frame hole might be larger in one bike over another and the seat posts might be smaller by a few thousandths. This would make for a sloppy fit and after enough cycles of creaky seat post, that aluminum will just crack in half. If I ever end up with a Swift, it will be a steel bike and a custom fitted seat post that I know is machined round for a precision fit. This is the only weak point in the design of the swift frame that I can see, other than the choice of material.
Perhaps the builder could beef up the frame with larger diameter aluminum and epoxy steel sleeves inside for the seat post. These could be closer tolerance and force the often warped, post welded tubing, round to create a true round hole for the seat post to slide into. All that folding and unfolding over time will make a sloppy fit causing early failure with heavier riders.......maybe user replaceable bushings/sleeves etc. could be engineered to maintain a tight fit and account for wear.