Dive computers aren't a replacement for a brain.
With OC cave diving I carry with manifolded twins. 2 computers and an independent SPG that gets regularly checked.
Dive plan and turn pressures are also on a arm slate so I don't fumble or them in an emergency. Additionally, I have a nice Dive Rite slate that has 2 layers so I also do a sketch map of the cave.
Interestingly. You missed the fact that over half the rebreather course is spent in emergency drills and driving the unit manually.
Still sticking with OC I think...