I had thought about signing up for the mutual account back right before they cancelled it but decided not to.

Have all of you mutual account holders ever used or do you regularly use the Comments section to note something along the following?

"Mrs XXX or Mr XXX will be checking in first, please accord them the same Diamond/Gold status of primary account holder."

And if you do, do you notice if it helps or not?

I only ask in case it does help, others might try to use that route. Although then you don't have enough room to ask for an upgraded room in the Comments section.