I did a search of the original BLF A6 group buy thread: Code now public! BLF A6 FET+7135 Light. Short 18350 tubes and Unanodized Lights Available
There are numous posts discussing the advent of the Astrolux S1. However, I couldn’t find any specific mention of any changes to the UI.
This is a review of the Astrolux S1: Review: Astrolux S1 3D Flashlight
It contains this drawing of the Astrolux’s UI . . . . . . . . . . . . . . . . . . . . . which is identical to BLF A6 UI:
BLF A6 UI reference: Code now public! BLF A6 FET+7135 Light. Short 18350 tubes and Unanodized Lights Available - #2899 by ToyKeeper