The only problem that I ever had in the SG was a couple players continuously farming me for wins when I was a vulnerable Mp3 and just beginning to learn the fighting system. However, that I am sure, is how most Mp3/4's feel.
Aside from that, most unconsented attacks are from ignorance, not by purposefully doing them other than those who insist on farming. If [b]Anything[/b] were to be changed, in my opinion, it would have to be the players reading the sign and not making ignorant mistakes, so as to get less people complaining about unwanted attacks.
But even then, that element, I believe, allows the players to learn to make a stronger defense in case of such an attack. If that defense allows them a win from that unwanted attack, the one who disregarded the rules, would learn not to attack that player again, lest wanting another loss.
I currently do like the SG, but at the same time, it feels like it's a little unrealalistic. When Mp3/4's become an Mp5, they're going to have to deal with stronger players who don't ask for wins or losses. [Unless, there is a sparring grounds for Mp5 that has that specific rule.]