My interface:
Head tightened- max, ~25%
Head loosened- lowest firefly, 5lm, ~18hz strobe, ~2hz strobe, SOS
No mode memory, full regulation, 18650 optimized.
My reasoning:
for the head tightened modes I have max first because I always want to be able to get to the highest mode a light has from off the reason of simplicity. After that I have ~25%, which Selfbuilt's measured in his review to actually be ~200lm. I like this because if I need to use the light on a high mode for a long time I can switch to this to concerve the battery life, and to the human eye the jump from 500lm to ~200lm isn't that noticeable. I haven't added any modes after this because I haven't needed anything between 200lm and 5lm, and because I like being able to switch between this and max quickly.
For the head loosened modes I have the lowest firefly mode first because I can turn it on at night without disturbing my night vision, or others that may be around me. After that I have ~5lm, which I can go to for a little more light if I am looking for something or want to light a path in front of me. After this I have strobe, both for the practical use of disorienting a two or four legged attacker and the impractical reason that my friends like to play with it. I have strobe three modes in because I don't want to activate it accidentally and because just the max output at night would be disorienting enough to an attacker to hopefully change their mind, and if not to give me time to give them a warning shot with the strike bezel. Next I have ~2hz strobe as a beacon for minor emergencies (if for example my car broke down in the middle of nowhere and I wanted to flag down another vehicle to get a ride). Lastly, I have SOS for major emergencies.
I have no mode memory so that I know what mode it will be in when I turn it on. With the head tightened I don't want to turn it in to only 200lm while thinking it was max, and with the head loosened I don't want to turn it on to 5lm and accidentally lose my night vision (or even worse, accidentally activate strobe!). I have full regulation because I almost always have access to a charger at the end of the day, and don't need to run the light for a long time very often. This way I know it will be at 500lm whenever I activate max, and if the battery is low it will give a warning. I have it optimized for 18650s because I use them for their capacity and recharging capability, and if I need to run it on cr123s I have a hand-written slip of paper in the battery tube telling me how to program it to do so (since if I need to run cr123s I probably don't have internet access).
On a separate note about the interface I like the 1 sec. delay when twisting the head to switch modes, so for example I can switch from firefly to 5lm without having the briefly switch to 500lm.
Right now I think my strobe frequency is a little to fast, but the frequency ramps so quickly in the programming that it is hard to get the frequency where I want. Other than that I really like this interface and haven't changed it since I initially got the light a year and a half ago.