After long and careful thought I believe you should be able to honor enemies again.
Sometimes you see some crazy mother f*cker on the enemy team trying his darnedest to win even when his whole team is feeding their asses off and you know what he deserves to be honoured. We all know his team won't honour because honestly know one honours a friendly after a hard lost ranked game. So let me the enemy who realizes whats hes gone through and what hes fought for give him a little something to brighten his day after that slaughter.