My brain hurts. I've been trying to read all the stuff on the various specs for the 6.4L, and there are "old" threads with the old specs and now newer threads with the new "MS-A0921" spec. It seems the common thread is to just stay with PUP and not worry about it. My 2022 manual basically says to use 0-40 with the "API donut" trademark, of which most 0-40 motor oils do satisfy.
I am planning on using the Mobil 1 Euro 0-40 since it comes in 5 gallon jugs, which does save a good chunk. It has the "API donut" which is what my manual says it must have. My masters coursework was on ICEs and I spent a lot of time in the tribology lab, plus 4 years working in an oil analysis lab. A lot of what I read obviously comes from folks who don't understand ICE tribology issues.
FWIW, the paragraph in the manual on the "tick" made me smile too.