So just wondering if anyone has a thought on the parks you need to lock in FP+ of really or what rides in September?
My thought is almost when we go in the mid-morning to AK we likely could just skip the FP+ there and hit something in the evening for another park like HS or Epcot instead?
MK = Really need for Space/Splash/7DMT
Epcot = Really need for Soarin/Test Track
HS = Really need for TSMM
AK = Don't really need it for anything and could focus on another park...?
Well, my real question for you is are you doing rope drop?
Working on the assumption that you're not and that you're planning to hit most of the headliners, here's what I'd recommend.
MK - you got it. FP+ priorities should be for 7DMT (11-12), Splash (12-1), and Space (1-2). Work in lunch after Space then hit the parade. Also try to get a fourth FP+ for BTMRR, which should definitely be possible, particularly in September.
Epcot - with tiering, this one's a bit more difficult. You'll want to reserve Soarin' in advance for 11am to noon and try to show up right at 11am. Additionally, you'll want to make Tier 2 dummy FP+s for any of those attractions with one being from 9-10am and the other being from 10-11am. Once you've ridden Soarin', immediately try to get a fourth FP+ for TT, which will probably still be available for much later in the day in September. While I'm doubtful this will be the case in September, if that TT FP+ isn't available, just do single rider.
DHS - a similar strategy plays out at DHS, which also has tiering. This time you're making only one dummy FP+ (9 to 10am). The other two you will use. Make one for ToT from 10:30am-11:30 and one for TSM! from 11:30am-12:30pm. Then, go to the kiosk and try to get a fourth FP+ for RnR. Like TT, I'm confident you should get one in September but just in case single rider at RnR is the backup.
DAK - Assuming you're staying later (i.e. until 5pm), FP+ isn't a huge necessity though it will probably help. Personally, I'd get one for KS, KRR, and EE at any time in the day. By the point that you can redeem a fourth FP+, it probably won't be necessary.