How much you weigh? The w/mph there seems a bit low.
Either way, there are "peak and fade" vo2 intervals you can do to both get used to doing that and also be able to judge your effort/speed capabilities doing that. As it really depends on the pack speed. If they're going faster than you realize and you jump, it will be doomed. If they're going slower for any reason, better. Like a lazy speed around a corner you could take much faster alone.
Weeknight worlds I've made the mistake on the shallower earlier hill how fast we were going up that sucker when I would jump and try to start a break with a couple guys. If folks are lazy that night and we're going up it at like 20mph, perfect chance. If folks have a hair up their bottoms that night going nuts and we're going up it at like 23mph......doomed doomed doomed.