Appreciate your angle. It was a mess of regulators, consoles and stuff — wasn’t a single piece harness. The stage was bolted to the twinset with the valve upwards. I didn’t see it being worn as I jumped early to make space and had planned a 2h solo dive.
As with every dive, my process — and one hopes everyone here — is to run strict checks validating gas, valves, breathing all regulators, gauges, wing, drysuit, etc., etc. Complicated and 'novel' kit configuration will hamper these checks and underwater procedures.