@Brittany Thompson that's a genuinely good question and I've seen it come up with other high-rate GNSS modules too. The honest answer is that on most receivers, CEP accuracy figures are characterized under open-sky static or slow-moving conditions, and the 1.5m spec for the MultiNav Pro+ follows that same convention — it's not a "low rate only" number, but it's also not guaranteed to hold the same tightness on a fast-maneuvering UAV at full 18Hz where your antenna geometry and multipath situation are changing rapidly.
That said, 18Hz is specifically why this module exists for UAV work — at 1Hz you'd be interpolating between fixes on a fast platform anyway, which is arguably worse than a slightly noisier 18Hz stream that your EKF can actually work with. Most flight controllers and autopilots (ArduPilot, PX4, etc.) are tuned to handle that kind of fix-rate noise through their own filtering, so the raw accuracy per fix matters less than the rate feeding your state estimator.
If you're seeing CEP drift that concerns you during aggressive maneuvers, it's worth checking your antenna placement for vibration isolation and ground plane coverage first — those tend to move the needle more than the output rate itself. Curious what autopilot stack you're running, because that'll also affect how the GNSS data actually gets consumed.
