Another 15 to 20 runs today, and getting to 350 within 110 overs wouldn't be an issue tomorrow. But needing to go at over 4 per over tomorrow means needing to step on it slightly - and I'm not sure if we would want to (or should) risk losing wickets in pursuit of one extra point.
Plus with Crane out there, he could well chew up balls.
Just continue as normal tomorrow. If the 4th point comes then great, but no sweat if it doesn't.
With nearly 300 on the board and Vincey and Daws to come i'd be tempted to tell Mason to play a few shots.