similarities Utorch S1 Mini, Klarus Mi1c, Olight Minis, and Sunwayman

Here is my best guess on how does the E16 lens work.
I think the central part refracts some light, focusing it forwards. It somehow redirects outward light towards reflector, possibly using total internal reflection for that. Then reflector makes a forwards-facing beam out of it.
Regardless if I’m right or wrong about that, I really don’t think this is just a TIR.