You are going to have a tough time satisfying all of those requirements. First, to clarify, in which ways do you want it to be smaller? Is diameter the most important dimension to be small? Or, how do you want to carry it?
You might first look at some of the eagletac lights. I think they make some of the smallest diameter 18650 lights, and also they make 2x16340 lights I think as well. These might have similar output and throw to your current light.
If you want smaller diameter still you will need to move to AA/14500 sized lights. There are some lights with pretty good output like the utorch ut01, but it is side switch only and it’s not very small in diameter. In small lights it’s more difficult in general to have high output and throw.
I actually was searching for a light with similar requirements as you, and I settled on modifying a thrunite T10. It’s small and has tail switch only, but the stock output and throw are not impressive. I used a dedomed XPG2 and FET driver, and it gets hot fast on high mode. See the mod here.