You want to plug in O2 so you must have a spare O2 tank.
You want to plug in diluent so you must have a spare diluent tank.
Also, you must plan for complete loop flood so you must have adequate OC-bail-out to swim out from your farthest penetration point.
How much gas/bottles are you planning to carry ?
Why complicate things instead of just carry adequate OC-bail-out and be done with ? But if you are planning to dive alpinist-style in the cave, then I have no comment...
