Thanks for the well worded reply. I'm considering a modified version of what I've described, and if you don't mind, I'd like to bounce the ideas off of you.
Instead of running 5x MC-E, I'm considering running 4x MC-E and 1x XR-E (The reason being that the 5 small reflectors used here do a poor job of focusing the MC-E. I'm thinking that swapping out one MC-E and replacing it with one XR-E might allow me to fill the MC-E donut with the XR-E hotspot.)
The power supply is still 8x LiFePO4 14500 batteries (which I'm considering charging in the modamag carrier with a 7s LiFePO4 pack charger to keep maximum voltage at or below 24v), and the Shark buck 3A is still the driver of choice.
My dilemma is how best to drive the one XR-E at the same time as the 4P4S MC-E. Off the top of my head, I've come up with:
a) run the XR-E in parallel with the 4P4S string of MC-E off of the Shark Buck 3A's output, using a lesser buck driver to bring the ~14.4v out of the Shark down to the 3.6V in requirement of the XR-E. This would steal some of that 3A output from the MC-E emitter's, but less than 350mA, if I'm correct, driving them at still more than 2650mA.
b) run a separate buck driver just for the XR-E, powered in parallel with the Shark Buck 3A directly from the 16-24V power supply. I'm not so interested in modes or dimming, but if I were, I think I'd be tempted to use a Shark buck 1A for the XR-E and control both the 3A and the 1A with a single pot or Remora... Would that even be possible, or would they not appear to dim to the same levels?
c) better ideas?