Yes, it would tell us a lot to know which freeper has this very concerned friend who is an expert at diving but isn’t aware of rebreathers and has a philosophy of not addressing specific content unless he agrees with the end conclusion that could be supported...
Who said I wasn’t aware of rebreathers? You just make stuff up to suit your story. In fact I answered that of course I was aware of them, but as your theory rested on a yellow air tank, a rebreather was entirely irrelevant.