@raspatan : Removing the shader would require editing the PK3. This is fine on your own PC against bots - and so long as you never share the modified PK3 with anyone else (pollutes the internet with damaged PK3 if you share online). At a LAN or online, this will create a checksum error too.

The next option is to create a patch PK3, which simply included the same shader from the original id Software PK3's.

Similar issue with LAN and online games, but in this case, the patch file would be ignored - which is safer than a modified PK3.

So, a difficult issue to resolve and a major reason why authors should never include base game files in their PK3.

Does removing the shader impacts significantly the map?