We sent out a total of 53 invitations and two reminders. At the end we got 26 filled surveys. We started analysing the answers. The experts could tell us whether they considered our elements are relevant or not. This helped us to know which elements and categories should stay in the final checklist and which needed to be update. Finally, we could incorporate the written feedback which the experts could give us at the end of the survey. To keep track of all our changes we wrote a point-by-point response to the written feedback. We plan to publish all this material when submitting our final manuscript for peer-review.