I don't know the route or terrain. A lot of well-planned courses have a "steep" or two. Tough sections that might test even a seasoned athlete. But I'm not a seasoned anything so I'd expect to give it my best effort, use a reasonable amount of energy, and make certain that I finish the ride.
Another poster mentioned the 12% difference between 30T and 34T chainrings, I generally considered gearing changes greater than 10% to be significant and noticeably beneficial. This is on the border. IMHO, the modification complexity and costs outweigh the benefits.