As I understand it cheat detection/evasion is an ever evolving landscape in any live game. What might be safe one week may not be safe the next.

In that environment testing on an alt account would still give them a single use get out of jail free card, but it won't provide enough information to then cheat safely on their main account indefinitely.

At best they might get a few weeks grace if they're ballsy enough to keep cheating, but if they keep using the same publicly available methods evermore it's not a question of if, but when they get caught.