I've had LSPI a couple of times with my 2016 WRX (turbo, direct injection, 6-speed manual).
Each time, it's happened at a low-rev, higher-demand situation such as being in 6th gear at 65 mph on the highway and then opening the throttle 50% or more in order to make a pass. Boost kicks in, cylinder pressures spike, engine management can't react fast enough, and, boom, you've got LSPI. Feels like a little knock, a stumble/hesitation from the engine for a second.
Probably not a concern with the F-150 since it's an automatic transmission that probably reacts very quickly and downshifts to get the engine up into its preferred range to prevent any cylinder pressure spikes.