The higher level thing isn’t true at all.
Every week I get around 30-40 fortune boxes on my main and maybe 1-2 of them are legs. lvl 106 main.
An alt I threw away a few days ago, about lvl 20-ish, got reckoning, ash creator, plat plate within 2 days of it’s existence.
I really wish the devs would give us the numbers to bloody tell. That or tell us how RNG effects us.