Just run 5w-30 full synthetic like the non-AFM (DFM) 6.6L truck motors run. It's the best middle ground for everyday use. You don't have the problematic lifters or system anymore, so lube it with a real oil that will do the job correctly. I've run it on my 2017 6.2L for almost 140k (178k on engine) thus far with no issues or oil consumption and I didn't do a delete.
If you're worried, do some research about CAFE and their gimmicks. Look at a 2016 Malibu 1.5L - requires 5w-30. Then look at a 2025 malibu 1.5L - requires 0w-20. The engine is the SAME, just the CAFE criteria changed so mfg are cutting corners to eek out mpg in factory tests. I say this because both of those mentioned cars reside at my house. And, because non CAFE motors have recommendations that reflect real life use and longevity requirements, thus running a heavier oil (read: correct oil).