when you state 'small' do you mean that the light has to be easily pocketable? or are you referring to length because lengthwise, all battery tubes for 1x18650s are more or less the same length and its the diameter and depth of the head that is going to be the variable.
if you want a thrower, its going to have to be a larger diameter with a deep reflector which adds to the overall length of the light.
The Jet III Pro ST is incredibly pocketable and has decent throw with decent spill but it is not going to throw anywhere near a Raidfire or even my budget Aurora WF600 (50+mm diameter with deep reflector).
Now if i could figure a way to get a tiny aspheric into a Jet III, that would make it a real pocket thrower.