FancyZones specify zone size directly

[robotdad]

Description of the new feature / enhancement

I have a single very large 4K screen. I would like to use FancyZones to configure regions of my screen to record with OBS Studio for demos etc. Ideally, I could specify this directly without having to use the drag bars which are not accurate for trying to get an exact 1920x1080 region for example.

I looked at custom-layouts.json but was very surprised by the rows-percentage and columns-percentage approach of specifying things there. I have no idea how to translate that back to specific sizes like 1080p.

Scenario when this would be used?

Recording demos.

Supporting information

I think the typical way for this scenario is multi monitor, but I only have 1 monitor and no room on my desk for another.