Been playing since launch with KernBypass (unofficial) even used it on the beta/pre-launch n no ban ever, I'm level 17 playing ranked rn, I also use choicy n disable everything except for KernBypass, I'm on ios 13.5 been jailbroken for awhile played cod n pubg with mods/hacks too. I've played probably about like 40+ games on the beta/pre-launch n about 20+ games on the global launch n no ban. I've also used apex mods/hacks big players, no recoil and aim assist and still no ban till they added anticheat I got ban, but I used crane to reset guest account n played legit for awhile after that.
Even if you unajailbreak you'd have to do a clean, clean, clean, brand new install I've heard some people have problems even after un-jailbreaking some files are left over n apex still detects it. You can also look at a tweak called succession if you want to unjailbreak to stock ios but on the version your at atm, unlike itunes it downloads the stock ipa of your version n restores it completely to stock all files get wiped like an iTunes restore but all trough your phone.
I'd still recommend trying KernBypass first because you'll lose pictures, messages, have to download all apps again, etc if you do a backup restore some jailbreak stuff will still be saved on that backup so you'll have to download everything again if you really want a full clean wiped device.