We never have used a 3rd party planner. We have all the info we need here on these boards. We are experienced with WDW.
Like many others, I plan the ADRs, then FPs and fill in the space between. BUT, unlike those that said they tour one ares, we don't do that.
We rope drop and hit many of the headliners early, regardless of location. We don't mind walking back and forth or around the park a couple of times. We get the big stuff done early, save FPs for 2nd park or later in day, if not hopping. We always park hop in summer with afternoon break. We sometimes hop in winter.
While my planner will have a specific order, we are experienced enough to default to the best plan for the moment. We adjust our plan based on actual waits, weather, crowds, tour groups, temporary closures and all the other unpredictable variables.