Replying to this and diy in general. First, diy mods do not need to be ugly. This is my setup. The xlab torpedo has a swiveling plastic bar made from a kitchen cutting board that is held with a ss bolt through the bottle's top (where the fin would normally go) with the appropriate plastic washers to fit. I move the bar longitudinally with the bottle, move the bottle up into place from below the aerobars, then turn the plactic bar 90 degrees to lock it into place (you can just see a part of the white locking bar under my left forearm in the picture). It could be even cleaner as the rubber band you see is there to hold my diy cap as I misplaced the original before the race. You cant see the cap here, but it was machined out of the same kitchen cutting board as the bar and inserted into a section of old latex inner tube so as to have a tight wrap which would form a tight seal.



The extensions are aerocoach angles. I ordered the custom 3d printed mount that matches the profile. Turns out my extentions are too close together to make it work so I shaped the perfect cross bar from 1inch abs pipe to have my mount just where I wanted between the arms then did a nice 3m electrical tape job. You can barely see it between my hands in the above pic.

Regarding 5.03.b by that definition any aero bottle breaks the rule. A bottle behind the seat breaks the rule. Heck, the letter of the rule would have disc wheels banned. Fortunately, the rule is generally interpreted as if it looks off, it is off.