One question.
Did you investigate this issue enough?
AND (and thats it):
I am very sure it's still possible to cheat like this.
I would not recommend this. PBO's are checked on launch and you will be put in the "TO BE BANNED" list by either VAC and or Battle Eye.
No, do no try this.
But it's exactly this.
PBOs are checked ON LAUNCH - that's it! So, i launch the game, i delete the PBOs after launching, I join a server - everything is fine.
"There is a way to bypass signature verification that is already going around, people are simply moving the plants / buildings PBOs back into their original folders before joining servers. Since initial asset loading is handled before server side checks and battleye are enabled, neither of these seem to catch this method." - Redklaw