To answer the questions - in a SCAAT implementation, we are using as many data points as we'd use in a conventional implementation. Only, they are incorporated sequentially and not assumed to be simultaneous.

Extraordinary measurement noise is easily attributed to the source or sensor responsible for it, since there is a single source-sensor pair per estimate. In practice, extremely high estimation rates makes it possible to simply discard the tracker data for such noisy measurements, at the same time, retaining the device autocalibration refinement.

The incremental orientation elements are maintained internal to the EKF, but the derivatives are those of angles themselves and not the incremental angles. This is because the angle derivatives behave as orthogonal vectors and do not introduce non-linearities in pose computation as the orientation elements do.