Oh well done.
Yes, I stuck the code up there for you, …interspersed with my rambling monologue as I explored 
I removed those extra canvas elemnts too, not sure if they were meant to be in there,
and some inverted commas from the name space, based on on this structure.
https://www.x3dom.org/inline-html-reflection/
for the <inline namespace part.
Talking of which, I’m not sure if it is a PG parsing bug/error with regards that line and the tag matching,
or Im a dufus and got something wrong, but you probably noticed and got orange pop up error warnings about the inline part of your code in PG.
so I stuck a possible bug report in here too.
Great to see you doing this!
The whole 3d in the web thing had/has such potential!
and totally overlooked.
seems mad to me.