I have a similar situation where I want the learner to complete a PickMany quiz, and then provide a short essay to justify their reasoning. The essay portion is intended to be relatively short and will fit fine on the same slide, and also allow them to easily change their answer as they investigate their reasoning. I want their choices and the essay to be reported to our LMS.
I have created a Freeform PickMany quiz and added the TextEntry as one of the choices. However, when I complete the question and use the Print Answers feature on the results slide (to simulate sending to LMS) it does show what entries I picked, including the TextEntry, but only the name of the TextEntry is recorded, not its contents.
So I created a Freeform TextEntry quiz and copied the checkbox entries over. The print view records the contents of the TextEntry but not which checkboxes they have selected. I'm thinking that I'll need to use a trigger to write the names of all checkboxes they have selected to the contents of the TextEntry when they submit.
I know I could simply have separate slides for each of these but I think they'll work better together. I'll keep working on it and let you know what I find.