I just made a fix for N!tmod and realised that the bug was still present in ETPub, ETPro and Jaymod. (NoQuarter isn't concerned)
The bug is caused by a missing animation when going from prone to stand while in FG42 scoped view.
If a player is using Scoped FG42 and goes prone, the animation is correct.
If he is still in scoped view and stands up, he will be standing up in 1st person view but other players will still see him as proned.
The bug also happens when players crouch in scoped view, when they release their crouching key, they are still seen as crouching, but really standing.
This way players can hide behind a wall or a box and then stand up and snipe without being visible to other players.
I honestly think this bug must be fixed on every servers to avoid unfair sniping.
Here is the package containing pk3 files for every mods mentioned above.
I hope to see it on every servers soon