I am using a ATEM Television Studio HD to switch a computer HDMI output. I noticed that when he computer is directly connected to a television the monitor has a mild overscan, when I instead connect via the ATEM the overscan is much bigger. It looks to me that the "tiny" input sources are not overscanned, similar to what is on the switchers display. I took a HDMI grabber to see the difference.
SetupPC with Intel onboard GPU, Linux.

Atem Television Studio HD

Minideck (HDMI output, downscaled)

The difference is over a full pixel zooming.

As customer what am I looking for? I consider this a bug or a property that must be able to be set by the end-user. I expect a pixel to pixel input to output, especially since the switchers "claim" not able to do any resolution conversion. If zooming is applied, it is non-sense not able to offer a full upscaler.