Why would you not do any firmware updates? They do those to address issues like this.
I still think you're making a mountain out of a mole hill. I've shot tens of thousands of frames on my G9mkII, I've only seen the purple fringing thing one time, and it was an easy fix in post. Plus, I do suspect it's a firmware issue, not a defect in the sensor, maybe it'll get fixed in a future firmware update.
I did the firmware updates (afterwards) on this camera and previous camera when received before going out with it.
I just wanted to test the camera before firmware update and before any settings tune-up to my taste, to ensure it was not related with those.
I too have shoot a few thousand shots already with the first G9 II and for sure have a plenty of shoots without the issue or barely noticeable, but on some the issue is there and very noticeable to me.
The problem is that the issue IS there. I will not accept to pay a such a price for a camera that have this kind of (unacceptable to me) gross odd issue... in fact even if the camera would have cost half of the price, with such purple issue random artifacts I would return it anyway.
I purchased the camera to have not only a bigger resolution, new better focus system, better iso sensibility, better dinamic range, live composite, bigger buffer, etc... but will not accept to have odd artifact like this randomly, or not so randomly as now I know when they happen, that is related with sun in the sky at certain positions for light angle...so I cannot use a new (supposed to be higher end) camera if sun is at a certain angle ?!? that is a big no to me, sorry, maybe for other is acceptable, I can accept that without a problem, just not to me.
Let me state that I am a longtime big supporter of the m43 system, have purchased at least 10 bodies and 19 lenses, and purchased the camera as a natural evolution of the system for the new functions, despite finding it a bit too expensive for the upgrade, but still dive in for it, as I stil believe in the system and it's advantages.
Initially requested help for the issue, now issue is identified and replicable, just not the rootcause of it... I believed to be a one isolated case and purchased a second unit after returning the first body, sadly the same issue is present on the new body, so I am scratching my head deciding on how to proceed from here...
I would love to see this fixed and if is simply done by a firmware update, even better, but I have to consider a few things:
a) I have a time window to return the camera, that I should not ignore...
b) I am not willling to be shooting with the camera with such issue present, so the camera would be staying put at home and I would be shooting with older G9. I had too many ruined images, it was "just" a family holiday this time and for sure many are just relaxed causal shoots, but still annoyes me, a lot... but I do a lot of other shoots with models that I am paying for... and events that are to be paid... (even if I do not live from this) so, cannot use a camera that I will not trust or that fear that will ruin images of those sessions.
c) I am not the kind of guy that purchased a camera and use a vanilly entry level lens (but nothing against who does it) , I invested in higher end lenses like Pana/Leica 42.5 f1.2 and several others, to have an edge of better quality images at a substantial extra cost... what is the sense to have a new camera (that costed a lot) where odd unwanted artifact are "added" in the images ? no sense at all, to me at least...
d) I am not willing to stay with the camera waiting for a FW to show up, without any warranty of solution in acceptable timeframe...
e) Typically camera prices go down over time... and I risk to lose money on the camera withou using it... not in the mood for that either...