After delivering the session, you will be offered feedback from your peer evaluation. Based upon this and your own thoughts, you are then required to produce a short professional development plan (max 1500 words) that critically evaluates both the design and delivery of your session and make suggestions on your own professional development in the area of teaching. (Source)
From Open Data Registered Trainer assessment google doc after a demonstration of their training, an applicant is given feedback, and asked to respond to it in writing.
Generalized learning objectives are provided, along with a typical rubric for feedback, which is, like most, subjective on a scale. There does not seem to be any portfolio type evidence attached to the assessment, and the process, while sound, is rather labor intensive (a lot of manual process steps)