Posting this here so that other folks can find a solution if needed (or so I can find this post when I inevitably run into this issue again in the future)!
I was asked to produce a custom Survey123 report that showed the values collected by a field survey team, and returned the value "NA" if the team had not populated a given field.
After trial, error, and a bit of back-and-forth with Esri Support Services (thanks, Poulami!), we ended up with this:
${if name == null}NA${/}${if name != null} ${name}${/}
This example evaluates whether the field "name" is null, and returns "NA" if the statement name == null is true. If the field is not null (name != null), it returns the value stored in that field.
Happy mapping!
