The ISC Megalodon CCR requires the electronics be turned on while the unit is opened up. This is viewed as a positive by some and a negative by others.

My personal preference would be for control at the handsets with a water activation feature so the head wouldn't need to be removed on the boat. This can be a PITA on a rolling boat, and the alternative is turn it on at the dock or garage, running the batteries over a longer period of time prior to the dive. This means that you have to have a higher voltage at startup to assure you don't go below nominal voltage for solenoid activation. This happened to me on a dive last year, and the solenoid stopped firing.

Diving a RB is a bigger responsibility than diving OC. Checklists and predive checks are a must. Forget or ignore them and it is a matter of when and what will happen to you. Complacency is not a word mentioned around avid RB divers. The need to prebreathe the loop alone should indicate an electronics failure/shutdown. You can't prebreathe a RB without watching your handsets. One of the ideas of prebreathing includes setpoint verification.