From my own understanding, VAC has to get the correct signatures of the cheat to make it 'detected' (to be VAC'd using that cheat.) AW and cheats like that have protection in place to hide that.
FaceIT AC and ESEA, have a system of which will detect an Aimbot even if it's low FOV, by calculating if it's humanized or not. Another thing being; ESEA has an 'Always On' AC, meaning if you mess up the code to a pasted, detected code, ESEA will detect and ban you, even if it's not running I believe. ESEA goes through all running processes too, making it very difficult to cheat. If it finds something it believes to be 'suspicious', it'll likely ban you.
It scans physical memory for signatures. ESEA has kernal access to RAM.
To clarify; if you create a cheat that's UD on VAC. That doesn't mean it's UD on ESEA. ESEA has insane measures of cheat detection, and each update contains more ways to detect. They don't ban people unless they have concrete proof that the player is cheating (i.e. Suspicious processes, aimlocking, computer calculations marking inhuman movement etc) Regardless. ESEA is like a rootkit, whereas VAC is more surface-level. ESEA has access to drivers, process, physical memory signatures and a lot more.
If you know anything about how "anti-cheats" work, it's a cat and mouse game. The problem is ESEA has the upper hand because Jaguar is the only person who can even look at the code, much less even work on it. Therefore if someone is trying to code "ESEA PROOF" cheats they need to figure out how the client detects and deals with these cheats. If they can't, then it's a hit or miss.
If you do manage to find someone who has a ESEA proofed cheat, with evidence, it would not be cheap whatsoever.
Hope this helped.