All HDS lights have basically the same interface and its very programmable and flexible, but the basic layout is a 4-mode light with only one mode available from off (not counting the secondary momentary). Then once the light is on, you can access the other three modes using these inputs -- double-click, triple-click, click-press-hold. Long-press while on also functions to access the click-press-hold mode in a momentary fashion. The actual function of each of those 4 modes is fully up to the individual user to program how they wish.
It sounds really complicated but its actually quite natural when you're actually holding the light.
Your proposed UI sounds more like Zebralight to me, and if I'm honest I think Zebralight's is better than yours. Zebralights have 3 primary modes (ignoring sub-modes for now) and those modes can be accessed from either "direction" from off. From off, press-n-hold the button to cycle through the modes starting in low, so it goes low > mid > high over and over as long as you hold. Release in the mode you want. OR from off, you can single-click to high, double-click to mid, triple-click to...well, strobe. But it used to be low before strobe was added to the lights.
Honestly though, Olight's UI is really pretty great. From off, its got instant access to low and instant access to high. Or you just press-n-hold to flip through the modes until you find what you want.
But hey, if you really think your UI is better then make it. You can write it for amtel avr and flash it to any number of "hobbyist" drivers available from the common sources. There's a whole world of
hobbyist firmwares out there. Your addition would be very welcome