How do you change your default Output Set for email?

Hi! Now that we've moved to Prospect2 for email, I would really like to pare down the number of fields I'm importing from Tessitura through the default Output Set. We like to import new lists so that we can promote back the tag for each email to track patron engagement. Because Prospect2 is basically updating every field on a patron's record from Tess, it takes hours for me to import my massive newsletter list. And, I know that I can change the Output Set in the list view, but I forgot yesterday and I just really want to change my default.