Thanks for doing this much appreciated
I don't know about m1-III, but my m1-II reflashes about a minute. Maybe it depends of model and sd-card, but few seconds looks too short. Can you do it one more time from begining: download, unzip and flash, better with another sd-card?It looks like it installed ok got the steady light when starting up and then the flashing light after a few seconds.
Sorry no firmware stayed on 1.2
So, it seems that MkIII refuses to update to this firmware. Maybe it have additional checksum not known to oly_fw_tools. It isn't looks very promising.I tried carefully your MkIII firmware v 1.2. the duration of orange light was around 45 secs.
The firmware appearing in the firmware menu remained 1.1.
I finally installed the official version 1.2. Orange light around 90 secs, clock and langage reset. And I retrieved the 29' max duration with the MOV fine.
I remain very interested by a hacked version allowing focus stacking and longer film duration.