Just stumbled upon this new 3.3x3.3mm MOSFET.
I don’t understand this stuff enough to know if it’s suitable for our lights, but it has lower resistance than the 5x6mm BSC009NE2LS5IATMA1 that Lexel uses….0.7 mOhm at 4V and 1.15 mOhm at 3V as opposed to ~1.15 mOhm at 4V and ~1.6 mOhm at 3V.
Gate charge is way higher though (29 nC vs. 17 nC 0 to 4.5V) and a few parameters that I don’t understand seem worse as well.
Bump…I’m surprised to see no interest. Is there some problem with it?
Its new and expensive product (Mouser- 2EU). It have good parameters, you can use it for any flashlight driver.
Thanks for the confirmation. 
MOSFET technology has improved a lot over the years, but the new products are still expensive in small or large quantities.
For LEDs at <10A currents, Rds isn’t as critical because cheap FETs already have low enough Rds that power loss and voltage drop is insignificant. For example, a FET with an Rds of 5mOhm will have a voltage drop of 0.05V at 10A and a power loss of 0.5W. At that current, the lumen/current curve is pretty flat anyways.