Calibration in general is a known problem with the IMC294 sensor. It is very sensitive to both image capture procedures and the calibration processing. The residual amp glow issue is due to incomplete calibration by the Master Dark Frame. I have not had that problem to any great extent but think I understand where it originates. My own current "best practices" procedures have eliminated all traces of it for me.
The severity of the tricky calibration problems ranges from mild to severe for some users. Once the causes are understood, I think anyone can get good results with the IMX294 based cameras. The camera may not be for everyone but I feel it can be tamed and produce great results.
One thing I have found is that the camera driver offset needs to be around 4 or 8 not the default 30 or I get blotches of colour in my DSO images (not ones I want!). Also you have to modify your processing routine, there are plenty of threads on CN about it. Basically flats need to be around 3s minimum and use Flat Darks not Bias frames as they really mess things up. Dark Optimisation doesn't work properly either.
You are correct that once you learn how to best calibrate your data from the IMX294 sensor, it can produce very nice images. I am severely limited now by my ability to get the most out of my processing rather the camera.
I will note that the solution you are using, setting the Offset to a very low value, works mostly because it is clipping large amounts of data to black in the background. Once the background is clipped, the colored gradients cannot show up as they have been discarded. There are other ways to eliminate the great bulk of the background color by using a different procedure while gathering images.
I can explain what I have found once Luca opens his new thread as it is probably more appropriate there.
I also noted that you listed Outreach on your signature strip and also the atm-workshop.com. I am chairman of our local astro club http://www.midkentastro.org.uk and we do a lot of outreach so I visited your website which is very interesting and helpful.
I am also having to purchase a new laptop to run my new astro camera as my old one is rapidly grinding to a halt! So I will definitely be setting up the red night vision mode on it. I used to have a 32 bit program that did that automatically under Win 7 when run.
Does your setup also set extension screens up in red mode as well?
Sort of off-topic in this thread thread but it is your thread... Yes my club does quite a bit of outreach. We work with area schools, the local university, and one of the local cities to hold star parties for the public. It is a lot of fun and very rewarding also.
Regarding setting up Windows 10 for Night Vision mode, some things have changed a bot since the tutorial was written. The latest Windows update moved a few options around and eliminated others but the basic idea still works well. I will have to find time to update the tutorial to match Windows' new way of using themes. I have never tried the Night Vision mode on multiple monitor systems but since it uses the basic Windows Theme constructs, it should work the same on all screen simultaneously.
I can dive into specifics on getting the most out the camera once Luca starts his thread. In the meantime, here is a sample from a recent project to image the planetary nebula NGC6781 in Aquila. This was just over eight hours of imaging time from bright suburban skies measured at ~18.75 mpsas. I used my ASI294MC-Pro camera at Gain=200, Offset=30, Temp=0°C with 60 second sub-exposures. The data is better than it looks as I need to improve my processing skills more to get all the camera has offered me.
Full Frame: 8+ Hours on NGC6781 with ASI294MC-Pro
100% Crop of Frame: 8+ Hours on NGC6781 with ASI294MC-Pro
I am currently working on another imaging project from my light polluted back yard. This will for a galaxy group in Aquarius. I currently have 14 hours of data and am shooting for about 20 hours before I call it done. Once again, the camera has outdone my ability to process the data and bring out all the details.