Here's a good read again on FEL v MEL for anyone interested:
https://forum.blu-ray.com/showpost.php? ... tcount=119. I have also never heard of FEL automatically being 422, would like a source for that if it's true.
For those asking what the "best" profile is when it comes to creating your remuxes, the simple answer is if your device can play it, then 7 because that's what the original profile on the disc is. Theoretically, if you're converting from 7MEL to single layer 8, it should be the same, because the EL contains no extra picture data. But if you're going from 7FEL to single layer 8, then you're literally discarding additional data that's used to recreate the original image. This is all a bit moot at this point though since no streaming-only devices today can properly play FEL titles. These devices simply don't have the capability to instantiate the two simultaneous HEVC decoders that's needed for FEL playback. This includes the Shield Pro, where even though it's able to playback FEL, it's not doing it properly.
With all that said, don't do needless conversions for the sake of obtaining a "better" profile. Do conversions only if your device is not capable of playing something without it. E.g. for the shield, just take what makemkv 1.15.4 gives you, it's that simple.