Sounds a bit complicated to me, how many bottles regs and valves do you want to keep track of?
I'm weighted to be about neutral with empty tanks on the unit in fresh, add 2kg for sea. Torch reels etc makes me slightly negative and the bail outs a bit more negative again. I can just about hold a stop with everything nearly empty - on the loop, so could drop a bit more probably if I planned for draining the loop, but it's comfortable as is.
All for redundancy but I can already use both bail outs in the loop and have ability to add a spare o2 1/1.5/3l on the unit. About only thing I don't think I could use easily (the QC is slightly different because of AP being weird) is my suit gas but if it comes to point of being that desperate to get 1.5 litre of air into the loop I think day is probably well fucked and I can just hold the pipe on.