Sorry, the 700 and 750 don't have sufficient margins in operating current range to hold regulation. As such, they will not be offered.
Instead, a full step down converter will be offered in the near future. Same small board size and it's possible that a 1A version will be available.
I have some prototypes of the stepdown and results look very promising that the stepdown will hold high 80% efficiency. Couple that with a MAX operating voltage of 16V allows possible combinations like 3 1X123 (~9V) and stepping down to drive a 1W for example.
Using the Stepdown, one could use a 3X123, or a 2X123 as in the McLux and still drive a 1W.
For a 5W, one could use a 3X123.
Those playing with multiple AA cells in a D holder could easily come up with nice battery combinations that would result in 9-14V and generate good run times for a 1W or for a 5W.
I think there are more battery and LED combinations using a stepdown converter than there are in a step up configuration.
Wayne