Ljutic, good work.
As far as the dimple on the firing pin. I could not judge how deep it was from your video. However, I believe I know the cause.
Upon recoil the unfired round slams back into the recoil shield. Since there is a firing pin as well there, held by a spring, the recoil force will naturally cause a small pseudo strike. A very light one. The top barrel will always be deeper than the bottom, in micro measurements.
To get around this light strike, either use stiffer firing pin springs or set the firing pin deeper. Of course this would mean a longer, harder trigger pull.
Or redesign with a cartridge retaining gap design.
But the designers probably felt the dimple was inconsequential as do I.
But again, you were there, I wasn't.
Please keep us apprised of the situation.