Rootkits anticheat is horrible bro, bc someone can hijack your PC directly since they own highest control in your system
I'm not saying my idea is good, but if cheater compete against other cheater & bots in secret lobby they'll grow tired on their own, finally they'll realize they got bamboozled by the game itself
Finally for countermeasures if cheater itself wanna play back in normal lobby the game itself will reset their stat/items/rewards/achievement back like they create account for the first time or make cheater pay huge sum of money to devs for harsher punishment