Vertex weighting is probably waiting for Vertex shader support in Blitz3D (this is available via DX8 or ARB extensions to OpenGL). Implementing vertex weighting any other way would be unlikely (from what I've seen Mark prefers to do stuff the easy way, and all power to him).
Vertex-shaders essentially give you vertex-weighting for free.
Vertex-shaders essentially give you vertex-weighting for free.