I have an idea for a design change to the Emag. I know AGD is willing to accept ideas from players (the 6 pak comes to mind) so here goes:
Instead of the current on/off valve that requires a large force to operate use a "side block" type of on/off valve instead. What I mean by "side block" is one that blocks the flow of air in such a manner that there is very little pressure required to operate the valve. This would allow a smaller solenoid and smaller battery. To maintain the reactive trigger in manual mode the electric/manual level could also operate a second on/off valve that would allow/block air to the top of the main on/off valve.
The following is a simple diagram of the type of on/off valve I mean.