It would be great if Turf not only supported calculating the axis-aligned envelope (bounding box geometry) but also a not-axis-aligned envelope, for example like shapely and PostGIS do.

This can naively be implemented by rotating the convex hull of a geometry, getting the axis-aligned envelope of the rotated, stopping when the envelope has a minimum area, and then rotating the axis-aligned envelope by the angle when that area was reached. But I'm sure there is a more efficient algorithm.