Degrees of Earth between neighbouring sub-points, at most; the floor below may leave a step over it.
No step is longer than this, however slowly the sub-point moves: the ceiling that keeps a barely-moving figure drawn at all.
No step is shorter than this, whatever the bound asks: the floor on what one track costs to draw.
How a Ground track is sampled when the bound is a ground distance rather than a clock: no two neighbouring points further apart along the ground than
maxSeparationDegrees, at steps between the two limits.