It will be quite the feat if you can manage to cigar grip that configuration!
. Alternatively you could use an R2 3.7-13V drop-in from LumensFactory, in my experience, they have a better color temperature (less blue) and tighter focus. The resulting runtime should be about the same.
Eric
Do you have a link for this module? I need something for my 2x18650 that can also run on 4x123. (Which rules out Malkoff)