Left4Dead2 Visuals Multihack

Why is no spread detectable in community servers but not no recoil? I haven't tried no recoil yet because of the unknown risk, and I don't understand the difference between method 1 and method 2

use only method 2, method 1 will be removed next update since its not really working

I'm still scared to use it, because the detectors seem to often scan both no recoil and no spread, and no spread is already detectable.