Hey ,
I must start off with saying great work on this. Its nice to see someone trying to release a toolset like this for free. 
As a C# .NET & HTML5 developer by trade, this is amazing to see and would be a lot easier to use than UMG in my opinion.
One thing though,
For some reason, unknown to myself, the performance of the webpage seems very poor compared to loading (and using) it in Chrome, Firefox or IE. It seems to take a second or two to register my click/hover etc. onto the screen. Would you have any ideas as to why this would happen?
- I used your example hud, changed the url to my local url and updated the tick via the Game Mode (as recommended).
I do not have problems with FPS with my system (in-case that was your first thought)
Thanks for any help. :)