I have acquired 3 atma sets.
1 and 2 true
3 false

Unverified:
The rng generator appears to be regional and time based.
Using random zone jumping every 5-10 fates netted an atma every 20-30 fates. (I have seen 2 100 fate gaps but those were rare)

Best advice, pick a number of fates you are comfortable doing in a day and stop after you hit that point. Good luck on "banging your head into the desk part 2: the second lump"