Lesson Learned in "Edit Columns" for Smart List Subscriptions
I contacted Marketo Support about a potential bug and learned some helpful info that I thought the community could benefit from...
I set up a Subscription to a Smart List and edited the columns to include info about "Last Interesting Moments." These new columns didn't show up when I went to download the report in the email notification. I learned from Support that some fields require a Marketo ID as an additional column in order to be exported. There isn't a list of all fields that need the ID column. To be on the safe side, include ID as a column for Smart List Subscriptions.