You say the system is unfair to the lower rated player, But if you were indeed rewarded for winning 2 out of the 5 games then this would be unfair to the higher rated player as this could mean that even though the higher rated player has won the match they could take a drop in their rating.
The BKR state that a winning players rating will not drop.
I think the easiest solution would be to play only single games or alternativley, Make sure you win the match..
:D