I would be okay with the addition of a timer as an option for custom matches but whether it counts up or not, if it's on by default and in almost every match I play, I would feel like it would damage the soul of the game just by existing and reminding you every second you've spent/have remaining, as opposed to the periodical reminders of referees in events.
Though it can certainly blend into the game if you design the timer well and make it look all steampunky. Unfortunately, the Skyball timer - which I assume is the most obvious place we'll get a timer from if at all - does not have these qualities, and even if it did I am still conflicted on whether I'd like to see it in default matches.
