I have tried factory reset for astrolux EC03 but with no success.
I have tried 3 ways:
- Loosen tailcap, hold button, tighten tailcap, hold 3s
- Click 12 time, hold 5s
- Click 13 time, hold 5s
I am still waiting for your help
Astrolux EC03 uses an older version of Anduril, that does NOT have the Factory Reset function.
The same old version of Anduril is used on the Astrolux EC01, Sofirn SP36 BLF Anduril, Sofirn IF25A, all of which do not have the factory reset function.
other comment: the Haikelite HK04 uses a somewhat newer Anduril version than the above flashlights, but also does not have factory reset function (but at least the HK04 has “manual memory mode” and “2-level-brightness lockout mode”, which the above older Anduril-version flashlights do not have.
In my EC03 and SP36 BLF Anduril working Loosen tailcap, hold button, tighten tailcap, hold 3s.
Interesting, looks like they updated the firmware version on the latest batches.
I tested another EC03 5700k which I just received, and indeed it now has factory reset — I did a firmware version check (15 clicks) and indicates it’s now using firmware 2020-03-18.
The earlier EC03 I got still uses an older firmware version (no factory reset, no momentary strobe, no 2-level lockout mode).
I don’t have a new SP36 BLF Anduril though.
But I did order a BLF Q8 Anduril, that has firmware version 2019-09-28 (ordered May 2020, arrived Sept 2020).
It looks like Sofirn is now really updating the firmwares on their Anduril flashlights.
(SC31 Pro came with Anduril firmware version 2020-03-18)
WARNING: Do Not Look At The LED 
Astrolux FT03S (SBT-90.2)
loosen tail cap hold power switch down than tighten tail cap keep holding power switch until :
led comes on with a flash than turns into strobe mode and ramps up than gives a bright flash and goes out
factory reset done