1. Start with a nice curved FI edge, which becomes shallower as I approach the center of the rink, in preparation for the edge change.
2. Meanwhile the free leg on the inside edge would move slightly into the circle. I think this is probably that the free hip leans in more, to maintain the curve as the edge gets shallower.
3. On the edge change, pull the free leg (or hip) back over the tracing to get a nice regular FO spiral position.
Overall, the movement should be slight, and hopefully the free leg doesn't drop. I managed to have a friend video my spiral sequence in June: