When selecting persons such as family members with shared events, when you select spouses tab add check box to spouse and click children have check boxes so you can select each child. This would be a lot easier then scrolling up and down list to find them especially for long lists of surnames.
If such a feature existed, I think it would have a problem. Namely, the witness list might not be in the order you would prefer and I don’t think there is a mechanism to change the order of the witness list. I don’t use the Add Multiple People option in RM7 for this reason. Instead, I add one person at a time and I add them in the desired order.
I’m was thinking about when doing things like census records. Under RM9, It doesn’t seem to matter what order I enter them in, I always select the wife first and she is sometimes at the top of the list and other times she is at the bottom.