cl_dynamiccrosshair 0 - crosshair is static when we are walking but not when we are shooting. That's what I meant by saying "half-static". cl_dynamiccrosshair 1 - crosshair is dynamic when we are walking and when we are shooting.
There is no other options to change behavior of the crosshair, so we can't make him "full-static" with commands. It means, they (server owners) do that with some plugin or script.
So, you are saying, I can't do anything with that?
Sounds you're using nosteam client aren't you? use cl_filtercmdstuff "1" and set your config.cfg and userconfig.cfg to read-only.