...I had found and tested (in counter-strike: source) custom VPK files,
where material files have edited to active transparent effect.
- These worked even in sv_pure 2 mode server.
- These custom VPK files have same
"public_key" as game original VPK files,
which bypass sv_pure check automatically.
This should not be possible unless someone have got
"private_key" from Valve,
figure out
"private_key" signature,
or somehow hacked VPK.exe/VPK file to set
"public_key" in file.
Like always, VAC not check player material, model, sound, etc. etc. files.
However,
CS:GO not have this feature.
So I don't know, how this game check player VPK files.
Maybe it is easier to customize cs:go VPK files... I have not tested.
What I try to say, I assume game VPK files are joke and sv_pure won't do
with those files.
*edit
Best anti-cheat is auto-ban best fraggers in match.