I would have liked my Twisty a lot more with 5 levels, but not having a button sure made programming and extremely daunting experience.
I agree a button is needed for ease of programming when there are only 4 presets, and to access ramping.
Im not sure how much programming is needed when using a rotary dial that can access all 24 levels by ramping, without any clicking involved.
One thing that is not on the HDS Rotary dial is Strobe, but that could be added at the end of the ramp. Or the way the RRT0 does it, strobe is to the left of the off detent, all the ramping levels are to the right.
Im not sure there is a need for a button, except for momentary ON. In conjunction with a gun, it is likely that a momentary tail button would be preferred, so there will still be a place for the HDS Clicky. And it will have ramping too, controlled by the button.
To provide a tactical momentary On, with a rotary dial, It might be possible to create momentary strobe by requiring holding the dial against a spring loaded stop. Same with Maximum.
It will be interesting to see what Henry has up his sleeve