I know there are plenty of examples about of the microlensing issue and have searched extensively, what I was looking for are some example raw LRGB subs which display the issue as I am specifically interested in something I have not seen really delved into. I am interested to see if the reflection issues in the ASI1600 are wavelength dependent and if so, what portion of the spectrum are they most evident at. I did get hold of some RGB subs but they are relatively short exposures without many really bright stars so the issue is not evident enough in any of them to be useful.
As for the ASI294. I think they have a fairly undeserved bum rap regards calibration. I recently, finally uncovered something like the issue that they are supposed to be notorious for in an image of mine, but it took an image where I have over 100 subs to stack and average the noise smooth to be able to profitably stretch the data hard enough to see it. I don't do anything particularly special by way of calibration, I shoot about 50 darks at the gain, temp and time I plan to use to create a master dark in APP (I used the same one for six months before I saw calibration issues slipping through and made another) Likewise I shoot about 100 flats and the same number of dark flats to create a master flat, making sure to keep the exposure time long enough to have the off chip electronics doing the work. By what I have seen the biggest calibration issues arise when exposures below about 4 seconds are used to create flats, when the SOC takes over the timing and circuity is active on chip that is not active for a traditional light frame, changing the noise profile.
My bigger issue with the 294 was reflections which were in some instances staggering but which were 99.99% resolved with a UV-IR cut filter. My interest with the 1600 is if that turns out to be a similar effect and similarly controllable with filtering, but I have not found that discussed as such.
I have some difficulty in smashing the ASI294 up too hard for deep sky when I have done the two images below with one without any particularly tangled processing steps. Most of the defects I would criticise in these two amount to shooting them through a $450 refractor with visible bloat in the blue end of the spectrum, at least when focussed using an undebayered RGGB sensor output. If it was not so many steps I would be tempted to focus then refocus while displaying only the blue channel to see if the blue can be tightened up, if so I could work out a focus offset and shoot two sets of subs, one where the blue channel was used and the other where the red and green were, splitting them out in APP and recombining the bits I want. But it is a lot of work to get around a dirt cheap frac's limitations.
https://www.astrobin.com/full/yypxc4/B/
https://www.astrobin.com/full/fvqi6n/B/