While breaking Pokerstars TOS (like every other player) and looking on PTR, I came across three players that have all followed the same pattern.
All of them starting playing at 200nl, played similar numbers of hands at similar winrates (if breakeven is a winrate). They all moved DOWN to 100nl within a 3 day window and repeated the pattern. They then moved DOWN again to 50nl and continue.
I don't know if there is a way to determine if they ever play on the same tables or not (like the great researchers did on SS for the Chinese DON debacle) but this might be useful as well if anyone knows how to go about it.