Boundary.points are point_ids and not points

[adtzlr]

but before changing that (this is also not backward compatible), a unique name for all attributes/methods must be used for a list of point ids:

• points_id or
• points_ids or
• point_ids

We already have Mesh.get_point_ids(value), so that would be my personal +1 👍🏻 choice.

Then, after deprecating and removing Boundary.points, a method Boundary.points() should be added, which returns the boundary point coordinates mesh.points[Boundary.point_ids].