Can we customize the virtual keypad layout in Nomad offline?

The virtual keypad is not configurable. Magic sheets can be whatever you want them to be. Laying out light plots is just one of their many uses. They can be custom interfaces, feedback info, LED visualizers, and many other options. You could lay out a custom keyboard on a magic sheet if you wanted to match one to the Ion layout.

I suggest this thread for inspiration on MS can do:

https://community.etcconnect.com/control_consoles/f/eos-family/12208/share-your-magic-sheets

ion facepanel 2017-09-04 12-06-58.esf

this is an ion facepanel i made some time ago. i moved some of the buttons to make them fit better on screen, but that should be easy to correct.