I don't think it's 3.7v it depends on the ohm of the dual coil..the LT limits the output to around 2.5 amps draw..which is low at 3-4v range but if you were using it at 6v and drawing over 2.5 amps that put's a lot bigger amp drain on the battery.
I think they easily could be safe with a 3.5a output limit but I'm not sure they could ever get up to 4a in a single battery boosted device that goes to 6v..if my thinking is right a 3.5a output draw set to 6v would put a 7a+ draw on a almost depleted battery.
So over that would be getting to close to the limit of IMR's..from what I've read AW's have a 10a limit..at least until they come out with a higher amp rated battery..but even then you have to worry about users putting a lower amp unprotected battery in it.