Automated donation acknowledgements using triggered Wordfly emails

I know there are other orgs doing this, but I can't seem to figure it out.

We're trying to create a triggered email in Wordfly for any gifts under $20 to our Annual Fund.  I have a dynamic list set up that uses the fund, contribution amount, and relative date.  That all works, and the list is available as a recipient source in Wordfly.

The challenge is the output set.  I want to include contribution amount and date, filtered by the same criteria.  I have that output set built, and it works just fine to manually grab the list.  However, it looks like Wordlfy can't use output sets that have elements that can create more than one line.  Does anyone know if this is in fact true, and if so, what is your work-around?

Thanks!