In the RealSense Viewer, you can create a custom 'visual preset' file that, when loaded, will set the Viewer's configuration (including resolution) to settings that you have pre-defined. The steps for doing so are:
STEP ONE
Define your custom settings.
STEP TWO
Left-click on the icon at the end of the Presets option row to save your 'json' configuration file under a name of your choosing.
STEP THREE
After the Viewer has been closed, you can load your custom file back in with the load icon next to the Save one.
The Viewer's settings, including resolution, will then update automatically to the settings defined in the file.
If the only setting that you are changing is resolution though, it would likely be easier to teach your colleague how to change resolution themselves with a 2-step process (expand open the Stereo Module options, then select resolution).
