halocline
Contributor
Typically I have it filled with 50% Nitrox.. so would not want to spend a lot of time deep breathing off of it.
It is attached upside down on the right side of my tank, and typically is a 19 cf tank. The regulator is routed up and attached to one of my right side, where one would normally see an octo.
Some interesting ideas, especially later in your post, that to me sound more in the tech diving realm. The thing I wanted to respond to here is that if you're using a non-recreational blend (50%O2) I think you're clearly talking about deco gas, not a bailout bottle, unless you have a hard bottom of 60ft.
If by some chance an OOA diver went for this gas (thinking it was an octo due to the way the reg is routed) at a significantly greater depth there could be big problems. I guess it's a matter of judgment. I would handle this bottle exactly as a deco stage, clearly marked as such.