Thanks, yes it does help.
I'm going to ponder it all while waiting for my light, and mock up routines with the regular momentary switch light I've got, but as I'm planning on getting a rotary I'm thinking that A on max makes more sense than most other options. Moonlight is the default need that I have for a light, but with a rotary I'll just keep rotary on B and give it a habitual twist in the low direction when I pull it out.
I will have to go back and reread the online user manual, don't remember reading about Memory mode, or the PDF might not cover it.
My guess at overall best utility with Rotary HDS (without having one to mess with):
Momentary on
Memory on
Burst on
A: High
B: Rotary
C: most commonly needed utility level (15-60 lumens probably, will have to experiment)
D: Tactical Strobe
Thanks Quiksilver and Sparky's Magic for both of your information, very helpful.