The optimized plan is off and has been for while. I never use it, but then I go to the parks on a regular basis. I just use them as suggestions.
The most popular rides for FPs is Hyperspace Mtn in DL and Radiator Springs Racers in DCA. If you want to go on those rides you will want to take that into consideration. But RSR does have single rider, so if the FPs are gone that is a good option to take advantage of. The land in DL that is crowded first is Tomorrowland, so sometimes we start on the other side, where fewer people are after getting our FP for Space Mtn. or Star Tours. After Space Mtn. we will get a FP for Star Tours, then go rides in Fantasyland, but that does get crowded quickly too.
If I were there for two days, I would probably plan to go to DL first and then spend the next morning at DCA and close out at DL.
Peter Pan is ALWAYS packed. Just plan on a 40 minute wait, no matter what. I think the only time I saw it short was around 11pm when the park closed at midnight and that even might have changed.
Do you know what days you are going? Now there is Magic Mornings to consider too. If DL opens one hour early, that means the rides will have a line by the time you get there. (You could do DCA first, but that tends to be a shorter day anyway.) But I would probably still do that, especially if you are going on a day that is generally slow. Though the crowd charts have been off too.
Because of the construction of Star Wars Land, the traffic patterns are messed up in DL too and that might be messing with the plans.
DCA is generally the same all day. It gets busier as the day goes by. Toy Story Midway Mania does not have FPs and there can be an average of a 40 minute wait for the ride most of the day, except when it first opens.
Overall, depending on the crowds levels, I may consider doing the single rider option more often, to leave openings for having FPs for other rides.
I don't know if I answered your question or just created more! Let me know if you have others.