I got your code cloned and built.  I am trying to shoot some recognizable images with it but since it is mid-day here I need to do short exposures to avoid maxing out the pixel counts.  This means that the issue with short exposures that I mentioned before is rearing its ugly head.  I will try to get some properly exposed subframed and 2x2 binned images and/or captures tonight and let you know how that part of the code is working.  In the meantime though here is a packet capture of the problematic 0.25 second exposures.  I took a first exposure, which seemed to download just fine, then waited a few seconds and tried a second one.  The second one downloaded but it paused for a really long time during the download. Hopefully this capture has what you need to figure out why this is happening.  In any case though I will investigate the subframing/binning code tonight when it is a bit darker.

I pushed another branch called bin_no_deinterlace. This has the same changes as the other branch and an additional change to not deinterlace the frame if y-binning is enabled. I think this will work better, but I it would be nice if you could test both and find out for sure.

I Ben, I copied this file from the web repository into the above folder and everything seems to be working now. Great !