It's well documented that vehicles make more power and become faster after break-in. This is due to clearances in engine and drivetrain opening up in bearings, gears and piston rings wearing in making a better seal. The computer doesn't limit anything at least in Ford cars. Factory boosted is...
Some of the newer F150 5.0's had oil consumption issues(not sure on S550's). Maybe that could be the reason? I agree Shifting_Gears, sly attempt by the Ford folks.
Wear metals will be increased after track use and you generally want to change it out after an event. You can use 5w-30 year round without worry, 5w-20 is only in there to keep CAFE bean counters happy. Just use a stout synthetic if you plan to track it.
With fl-500-s, dealers will buy in 12 packs only, 820, 400, 910... Most of the lower volume filters come in individual boxes. At $14 that's just about as much as a Ford Racing 820s..