Jartex has some limitation with what they can handle with the staff and resources they have.
Jartex Anticheat is not that bad to be honest, it has kicked countless players which would have been a pain for staff
When you see a cheater, the best thing you can do is play well and beat him
Like lets say he is using aura or reach, just try to FB him
If he is using nuker, clutch
If he has antifall, pvp him on big flat land
Anticheat can help you too over here
From my experience you just need to make that hacker trigger his own kick
For ex. If he is using reach start making a tower, he will follow you and try to hit you
while pillaring he might attempt to hit you from a distance which is greater than normal reach which anticheat detects and kicks
What I mean to say here is that if you really want to win that game extend it as long as possible that way anticheat will get triggered eventually
Now the lucky case will be when you do ./staff after seeing a hacker and some staff is online on minigame server (not ingame)
Just invite that staff to party and give him hackers ign or warp.
A responsible option will be to record the hacker as well and report him on forums so that no other player will have to face that cheater again