I've had the same idea and I think it is a good one. The L0D CE would work a lot better on two alkalines than it does on one alkaline, in addition to on two NiMH. It might fry on two L92 lithiums though.
If it can survive a couple weeks of EDCing on 10440s, I think it should be fine on 3.0V worth of primaries. In fact that's probably the optimal battery configuration for it, I will test current draw on that setup (2x lithium primary) if I can get a hold of them.
There are a few variables at play -- one of them is battery internal resistnace. With a single tiny cell, theres' a lot of resistance to drawing so much current out of it, which causes some of the energy to be wasted. Adding two cells reduces the amount of resistance losses, as ideally, only half the current is needed to produce the same usable power.
In addition to that, the light has to increase the voltage from 1.5 up to around the 3.5-3.7Vf of the LED -- this conversion process is generally more and more efficient the closer the input voltage is to the output voltage.
I did a test using some moderately used alkaline AAAs (not the best battery) -- one one cell, power consumption was around .85A. On two cells, current was the same, but at double the voltage, so more than double the usable power is likely being delivered to the LED. Runtime should be the same on high, but with almost double the output. In that configuration, it's not quite as bright-looking as the 1A/3.7V 10440, but also doesn't suffer from 10 minutes of runtime on high, and excessive heat buildup if not the light is not held in-hand (to act as a heatsink). On 2x NiMH, current is 1A exactly, and looks a little brighter than the 2x alkaline setup. It should also have more consistent output.
Actually, if someone offered a 2xAAA tube for the L0D, I'd probably buy it -- that form factor is still fairly attractive (much moreso than 2xAA or 2xCR123 for pocket carry) as it's about the size of a pen. I'd run NiMH cells in there and enjoy something in between the stock high, and the outrageous 10440 high.