I'd say as long as you get there early to help set-up, even if you have to leave early, just let Matt know and it is not a problem at all. But, usually, the matches have been over about 3 to 4 pm. I can only assume Matt is going to be a little more efficient and the matches will be over around 2 or so.
The folks who show up 5 minutes before the shooters brief and then leave before their squad is done is what we really don't want to have happen.