We've tested for 2 nights now and it's official. Both weapon mods work great added to the .iwd but there's a catch. When you have a sniper rifle equipped you cannot use your knife. If you switch to your secondary weapon (non-sniper weapon) you can knife. This also happens with all weapons once it is shot out of your hand. You cannot use your knife unless you pick your weapon or another discarded weapon up.
Any suggestions to fix this or is it just one of the concessions to using the mods?