This is one of the first ASI2600 images I have come across.
https://www.astrobin.com/full/qoy3js/0/
I am currently waiting for more images to make a decision between an ASI2600 or digging a much bigger hole in my pocket with an ASI6200 (Probably mono, just to make the hole that much deeper again) as my hopefully soon to arrive scope has a 43mm image circle compared to a 43.3mm diagonal on the ASI6200. I plan to track down an M48 format adapter for my wife's full frame Nikon D3 to see if it really does cover that kind of diagonal nicely first.