I will talk to my manager tomorrow. We only have 10 support hours, but we could buy more, I really hope so.
Now, I figured out that in our case, the name #canvas in vtkWebAssemblyOpenGLRenderWindow is unrelated to the fact that I get a null, when querying using :
<HTMLCanvasElement>document.getElementById('anotherName')
The name canvas is from some auto-generated glue code from Emscripten. Emscripten is open-source, so this I should figure out. Once, we get a proof-of-concept, I really hope that we will reach out for some ongoing support with wrapping etc.
Thanks again and keep up the good work
Jens