Finding outlier points before triangulatePoints when extrinsics are known

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I have sequences of images I am using for cv2.triangulatePoints. From external odometry system, I already have decently accurate extrinsics of the camera.

If I didn't have extrinsic, I would find an essential matrix and cv2.recoverPose, which results in really clean triangulated points because I can use masks to filter matched points before triangulation.

However, when I extract ORB features and match using ratio test, and then triangulatePoints. Visually inspecting, I would most often get ~80% well triangulated points but 20% noise. On some frames, it is more 50% good points and 50% bad noise.

Is there a way to clean up these points before triangulating them? Thanks!