I am still not very good in driver electronics (only a general idea of what is going on), so no ideas about which one to use, but I do have idea's of how I think the MT-G2 could be driven well.
I will give a general idea of how I ideally use this kind of data to make my idea of a good useful flashlight, and I guess that is not so far from how some others in this forum think. (My game is usually not about setting records while being totally inefficient and burning through batteries in 5 minutes, that's another fun sport).
Using the MT-G2 most factory lights go up to 5 amps, even the ones that use copper boards (Eagletac). That is a good idea, great output and good for efficiency and gives a managable amount of heat. But in this forum we want a bit more and we are not afraid to get our hands warmed up. Maximum output is reached at 11 amps, but the light will be hugely inefficient at that current, a real waste of energy and probably not good for the lifetime of the emitter. My personal rule of thumb with copper mounted leds is to aim at about 3/4 of maximum output: the led is used very well, the visual difference with max is negligable and it almost halves the current neccesary for the maximum output (the performance graphs of all other emitters have a similar profile so this is valid for all emitters). For the MT-G2 on copper and maximum heatsinked 3/4 of max is reached between 6 and 7 amps, so that would be my ideal. In a flashlight build heatsinking will be worse, but I'd still go for the 6/7 amps . The led alone will produce -apart from emitted light- about 30W of heat at that current, so the build needs a good thermal path and sufficient surface area on the outside of the light.
One remark about why it is great to use these copper boards as opposed to traditional boards in flashlights: because the heat can get away from the led so easily, the temperature difference between led and body is less (I believe it is even much less), so the body can be allowed to get hotter while the led is still performing well. This is advantageous in two ways that help each other: 1) obviously you are allowed to make more heat (the led can be driven harder), and 2) the difference between flashlight body temperature and ambient temperature will be larger so a same amount of energy can be dissipated with less body surface. In practice: I have not tested it yet, but my guess is that when a copper board is well mounted with a good heat path to the body, you can continuously keep running a flashlight that is too hot to touch. One design consequence is that the battery compartment will have to be thermally more isolated from the head of the light than usual (i.e. further away).
Sorry, this is a bit of a long answer, and it is perhaps not even an answer to your question .