1280x1024 squished to 1280x960 in screencaps...officially supported resolution?

[borgman]

Just got my Screen Crab today, and did a quick test-run using an old-school 5:4 monitor (1280x1024 is still a common resolution where I work) -- the HDMI pass-through worked fine (image on screen appears to be 1280x1024); however, the captured images on microSD are slightly squished to 1280x960, leaving them slightly distorted (but still quite legible)

 

Is 1280x1024 an officially-supported resolution?    
(wondering whether I should expect it to work as-is, or if I should continue troubleshooting with another monitor)

If it's not an officially-supported resolution, is this something that I could easily hack into a file somewhere using the serial console?   
(I understand opening the case will void my warranty-- I'm not overly concerned about that if it'll solve my problem)

 

On a side-note: it would be nice if a future revision of the Screen Crab allowed serial access without voiding warranty -- I can understand not wanting to make serial available via USB-C to help keep device presence covert, but maybe it could be non-default behavior that requires user intervention to override? (e.g. enable serial over USB by holding down button during power-on)