I know that MRDs are not required for non-owners (who are still employed). However, I have not been able to find any specifics on what should be contained in a waiver signed by the non-owners (stating they do not wish to start MRDs). I have not even found if a written waiver is required.

Any comments or suggested reading is appreciated.

I'm not aware that any waiver is required. Generally the plan document would specify that no MRD would be required in the situation you describe, and wouldn't require an election or waiver.

The waiver is needed if the plan document does not specify the criteria for whom should receive the MRD's. If a plan has not yet been updated for GUST, then the waiver would be needed prior to the required beginning date.

Our firm has written our own waivers that just spell out the options and give the participants the right to choose. I have not seen an official waiver anywhere.