@Sarah Moore yeah this is a real concern and you're right to be thinking about it before you're 4 hours into a session and wondering why your heading is off by 15 degrees.
The honest answer is that any MEMS gyro — including the one on the sensors module — will drift meaningfully over that kind of session without correction. In-run bias stability on typical MEMS IMUs is usually in the range of a few degrees per hour under good conditions, but temperature changes, vibration from your motorized rig, and just the nature of integrating a noisy signal all pile on top of each other. Over 4-6 hours that adds up fast if you're relying on gyro integration alone for heading.
The good news is you've got the magnetometer right there on the same board, and fusing those two — even with a basic complementary filter — makes a massive difference. The gyro handles fast, smooth motion really well; the mag gives you a stable absolute reference to correct against. That combo is pretty much the standard approach for exactly your use case. If your rig has GPS lock too, that's another fusion input that can help anchor heading over long periods.
On the specific bias stability spec — I'd suggest opening a thread in the Dev Hub resources section or dropping a note directly to the team, because that level of datasheet detail doesn't always make it into the general docs but Moamen is usually pretty responsive about sharing it when someone has a legit application need like yours.
