Were any of these angels direct participants in previous “Free Will Experiments?”

Many of the angelics assigned to the Milky Way Galaxy were indeed prior participants in that same exercise of free will and were selected for duty because of that hard-won learning. The same situation exists for many of the human old souls who were involved in prior versions of the universe and attempted to succeed with a free will paradigm that failed and wanted to have another opportunity to overcome the limitations of the prior exercise and bring a successful conclusion. So there is quite a mix of histories of the individual participants with respect to prior experience or having fresh perspectives and to some extent newly strengthened capabilities for the task at hand.