Personally, I find it depends on the type of jump I'm approaching. There are some that when I'm walking, I've noticed are a whole lot bigger than they look. Willie is a bit of a goober in that he can get sloppy sometimes on cross country. Sometimes he needs a good half halt to say "Hey, you need to pay attention to this jump." There are also jumps that are more "gallop-y." They're jumps that are ones that are actually easier to take in stride without too much half halt. Sometimes it'll also depend on the horse I'm riding, especially if they're built a little downhill. When they're built downhill it's easier for them to get on the forehand while cruising around course so I'll always give them a good half halt before jumps.
I feel like just saying "Hey, I'm going to maintain one pace the whole course" is a little naive. You should go in saying, "Hey, I want to stay on pace, but I know I will more than likely have to adjust my speed throughout the course because of other factors." Weather, shadows, lighting, people, other horses, terrain changes, spooks, etc. will all affect how you ride the course.
"Always be yourself. Unless you can be a unicorn. Then, always be a unicorn."