a few variables here, but generally the “after long deco” gasses go on the leash, so pure O2 (in an ali80 180bar makes it almost neutral) and say a 50% nitrox (the touch of helium added for ICD makes it again nearly neutral) the beauty here is you can jump / flop or be handed them already on the leash at the surface so just clip them on to the hip D ring as your about to submerge, if your a stacker like me then you only have to swap the two under the arm as one will be non hypoxic (starting on top) and the deep one under it,Hello Alex. When you use this technique do you attach the cylinders on the surface or during the descent?
Even if diving with 3 I prefer leash to clipping the third straight to the hip D ring as when you reach back you can easily tell which clips are which, (UK diving in dry gloves) and I think foul clipping is less likely,
Honestly it’s really not as chaotic as it sounds, (some of my mates do this whilst driving a Suex with a camera the size of a basketball in front of them.)
Try the leash thing it works for me, once you’ve dived it a couple of times the cylinders of no real use until your shallow being out the way is far easier to manage, (already mentioned, Joachim’s Chanel on YouTube “inner space explorers” explains it best.