In most of those two-stage switches is a resistor for the low-level that you can by-pass. I have done that with some other lights.
If you bypass the resistor, you would get a On-On-Off clickie. You would need a new clicke to replace the one already in the tailcap. Which model is it?
My clickie was : off - low - off - high - off, I don't know yhe EYJ-clickie.