I had never seen that Maratac 1D/4xAA light before, it seems to tick most of the boxes of the emergency light of this thread. Reminds me of the BLF-version of the Lumintop SD10, that I indeed keep with some D-cells for emergency (as if I need a light in emergency, with 150+ of them already)
One thing essential for getting a BLF light done: a BLF member, or a few of them, who believes in it must carry the project, put loads of time in it, find and convince a manufacturer and patiently sit it out until the light is in production. Who is this going to be?
About the batteries: I suggested a few times elsewhere that a modern flashlight on AA batteries should not have 4 of them but 3 in series. It makes for a slimmer flashlight and you can use a very simple and robust lineair driver. This used to be impossible a few years ago but the voltage of the new leds have come sown so much that they can be run regulated at high output for most of the runtime of the batteries.
The only thing wrong with a 3xAA setup is that no serious manufacturer has made one yet with a high output modern led (suggestion: Luxeon V), the concept is just used with 3xAAA carriers direct drive on an oldschool XP-E led that has too high voltage to give real light. It will need a lot of convincing to get a chinese manufacturer make something that has not proved itself before.