How about adding a weapon selection window before inviting a player for a duel?
Like which weapon set would you like to use? You can have maximum 5 weapon set and minimum 1.So as soon as the players get duel notification he can see the selected weapons for duel eg * You have received a duel invitation from Satvik.soT[GgT] (ID: 10). Type /duelaccept 10 to accept it.(Weapons- Uzi,Sawnoff,Sniper,M4,Nades) + it will remove typing /saw and /sniper during the starting of a duel.If we know the weapon set it would be nice for opponents too.
We can have an option like default weapon set which can include weapon set which we currently have.
PS- Rage if you want you can quote this to your suggestion if you like my suggestion, so it would be easier for others to read