I have tested and like the Plan Builder in general. However, as a 46yo masters age rider, I prefer a 4/1, 3/1, 3/1 progression for Sweet Spot Base 1 & 2 alternative from Nate’s original concept. That means the only real way to do it is the “old” way (apply one phase at a time), without the Plan Builder.
I have applied my Base according to my alternative. When I complete that, I may use the past date option in the Plan Builder to pick up from there. As is, I need to manually apply the adjustments outside of a Plan Builder setup since it is not practical to do that on the calendar.