How much of a jump are we talking about? Is it jumping many meters away, or within the same general area? The REP does state that the odom frame should be continuous, but then fusing a GPS with data in that frame may not be the best approach.
What you could do (and something I've done previously) is to have your map frame be the UTM grid. If you're trying to plan paths from one location to another, you can determine the difference in UTM coordinates between the goal and current position, transform that difference into the odom frame, and then execute control commands with respect to the odom frame (which would be continuous if you don't fuse the GPS with the estimate). When you reach your goal in the odom frame, you can re-evaluate the distance in UTM coordinates (i.e., the map frame) and repeat the process until you've reached some distance to the goal.