Are you serious or are you just one of those numerous trolls that seems to sprawl these times?
You have no issues because you aren't using your hardware. I can also have no issue by leaving my motherboard on every default setting ^^ I currently have ...
Getting pretty close to a full year since these boards and CPU released, and each new BIOS update is still a dice-roll.
This was ridiculous 6 months ago... I lack words to describe how bad it currently is
You can use both, a 6400 MT/s has 2 of the same 3200Mhz modules therefore there is a total of 6400Mhz on a 6400MT/s.
Sure it might be more precise to use MT/s, but you won't change the habits of people using Mhz for the past 30 years
You said :
"Only proper ways to oc ryzen 7000 is per core co undervolt and async eclk 100 to 105 frequencies"
Which is false since a proper way to OC your CPU is to use an all-core CO. You could get better end result but that isn't "more proper" one ...