Client Letter Type

I am probably missing something, so excuse me if I am asking something obvious.

I know that the logic on the client letter looking at whether the return is coupled and the person isn’t dead to determine if the joint or individual client letter should be used. But I also see that on the Engagement form there is a field for Client letter type with several options in the drop down.

We would like to change the logic on our letters to use this information, but we would like this box to default to joint when coupled and individual when not coupled and deceased letter if the client has passed.

Is there a way in the options to set this?

Sometimes, even though the returns are coupled, we want separate letters.