Razza-frazza. I've integrated the SVG drawing code and it works beautifully. The only downside is a deeply geeky technical issue. Basically, drawing from the SVG files "taints" the map canvas and breaks the CORS security. So you can't export the map as an image after you draw an SVG graphic on it. That makes the new functionality much less useful.
Here's a related article on the security setting if you want to bore yourself. The convoluted "solution" suggested there still doesn't help with Shamat, since that uses local files, which are ALWAYS "tainted" in the CORS model.
https://developer.mozilla.org/en-US/..._enabled_image
I understand the need for internet security, but man alive I've been running into a lot of problems with CORS lately, both at home and at work. It's rapidly moving towards the kind of security typified by the "we can eliminate crime by killing everyone" mindset.*
* Known as "The Dark Judges Solution" to Judge Dredd fans.