Depending on what you *actually* get, and supposing this idea came to fruition along with it, 30 minutes would be perfectly acceptable as long as lock time decreased with skill (say MC for example), IMO anyway.
In fact this is the exact deal MA's get with dimach (mine is down to 10minutes 30 seconds ish with 1900 skill, Most 220 NT's have far more MC than that, i think), which to be honest would be completely overpowered if it had the same recylce time as aimed shot / full auto on the fastest recharging weapons.