Move towards using free functions on built-in properties.
OpenMesh supports changing the type of the built-in properties (like the vertex position), which is a great feature.
For this to work however, the types have to implement certain methods such as length() and normalize() (as member methods).
Replacing the calls to those methods by calls to free methods of the same name (and then implementing those free methods for the OpenMesh built-in Vectors as calls to the member) would make it easier to support new types for Points.
E.g. to use Eigen's Vector types with OpenMesh, it is currently required to use Eigen's "plugin" system, which can cause the program to fail in hard to debug ways.