I had a long running thread about his truck on one of the F150 forums.
https://www.f150forum.com/f118/465-000-mile-2-7-a-389552/ (a moderator changed the threads name after Pat traded. It was the "100,000 mile 2.7" since he did that distance in about it's first year......) Pat sold his 2.7 about 6-8 months ago. The truck developed some sort of transmission issue and at 465,000 miles he (his wife) decided it was time to bail. He's not brand loyal, so he's now driving a Dodge....... He replaced a throttle body and some sort of sensor during the 2.7's time with him. I bought my 2016 2.7 partly because of the good fuel mileage he'd been seeing. At 87,000 miles mine is showing 21.1 lifetime.
Valve's needing cleaning on either the 3.5 or the 2.7 F150 Ecoboost's is not an issue. I'm on the major F150 sites regularly and have YET to see a thread where that was needed. Talked about, yes. "old wives tale" comes to mind.