This thread is a couple years old, but I'll link the
ultrafire vs. L4 flood war for pictures of mofo's single cell rcr123 KL4's (middle of the 1st page). I.D.K. the specifics, but maybe something for the O.P. to look at for someone wanting a smaller L4.
And I.D.K. why, with so much new L.E.D. technology since the L4 was designed, has there not been more small lights with really huge flood. Especially considering how strong a reputation the L4 has had for so long now, I'd figure there'd be more copy-cat versions of it. A "wall of light" in something as small or smaller. or at least longer runtime by now. Do not enough buyers seek such small bright lights with so much flood that it's not profitable for companies to go there, or apparetnly still hard to top the L4 design? For instance, I would have liked the L1 to have a more flood beam like the L4, eve though it is not as bright. Although that one doesn't save much length vs. the L4, and is actually bigger around.
Just seems like now they should be able to have an L4, same size that has a much longer runtime considering the runtimes of L5 and E2L etc. Maybe they'll update it soon?