There's no proper way of contorlling weapon cursor visibility with script.
There is showHUD extended script, but the cursor param false also hides action menu which is very unreasonable.
Or we could use server something.cfg to disable or enable the weapon cursor but if we disable weapon cursor with thet cfg, we cannot enable weapon cursor with script in game.

I'd like to enable specific units in MP to use crosshair and others not, but there's no way to do it in simple way.

Please fix the showHUD - cursor not to hide action menu. You can add one more param to do it. why do it at once. it's never convinent for anyone.