Writing 3D WKT: Z in prefix?

When writing 3D objects in WKT, a "Z" is supposed to be added to the prefix, such that a 2D point and a 3D point are differentiated:
```
POINT (1,2)
POINT Z (1,2,3)
```
But as far as I tested, when writing 3D objects using the WKT writer of Boost Geometry, the "Z" prefix is never written, leading to this kind of output:

```
POINT (1,2)
POINT (1,2,3)
```
It seems to be similar for other types of primitives (`LINESTRING`, etc.).

Reading 3D objects with Boost both works with and without "Z" in the input.

Wouldn't it make more sense to add "Z" to the prefix whenever a 3D object is written?