Add Note Feature : No 7th with Scales?

I find out that you can only play triads while using the Add Note feature. Am I wrong ?

Imagine that I have a nice chord progression and wanted to add some extra notes (like 7ths), how can I do ?

Weird thing is if we could play 2 chords at the same time we could actually get seventh chords (like a C chord plus an E chords give a C-M7.

I also just realize the very little amount of chords available compared to the Model:Cycles (who also possess variations, as Syntakt does also)