Why not the P18, where the LR is really designed to shine?
AFAIK the issue is with current drain.. if you use any of the AW high drain limn batteries the increased load of the lr atties will fall well within the rating of the battery where the normal 16340s and 18650 are overloaded and have shorter lifespans. this is regardless of if the battery is a 16340 or 18650.
there is a post somewhere in these forums, maybe by drozd where he runs down the math.
g