Seems like the simplest fix to the quit button issue, if it is in fact a problem with not being able to quit once the next map starts loading, would be to delay the next map from loading a little longer. As it is, the length of games in the core modes is quite long, and there is a relatively short amount of time between maps. Leaving the quit button up for, say, 15 seconds longer than it used to be there prior to the patch, would be a good enough solution I think. That's long enough for a quick glance at the stats, checking to see if you got a battlepack, etc.