Is that really necessary? http://caniuse.com/#search=svg
IE 9 runs on Windows Vista... VISTA... VISTA... the antediluvian operating system that was widely hated. And yet, even that setup can load SVG images. You'd have to go back to IE 8 to find a browser that doesn't support SVG. That's Windows XP territory... an OS that Microsoft doesn't support anymore*
*Unless you're like the Navy, http://arstechnica.com/information-technology/2015/06/navy-re-ups-with-microsoft-for-more-windows-xp-support/
If SVG is converted to an image, the size could be humungous. That's a lot of weight added to a Hype project. How's pre-loading going to work? It seems like a waste of development time.
I think there's a much better use of Tumult's time... CRUNCHING IMAGES! Automatic "Lossless" compression of PNG / JPEG or GIF would dramatically speed up download times. This could be an export option. That would be a much bigger benefit to Hype developers and web visitors.
Yet, in the early days of the web, it wasn't as scary as it is now. Hackers have been incredibly successful and incredibly aggressive in recent years. To be a responsible web developer, I have to stop supporting these ancient web browsers. I've dropped support for IE 8. It's almost end-of-life...
January 12, 2016 - https://support.microsoft.com/en-us/gp/microsoft-internet-explorer
That's a pretty good guide. If Microsoft doesn't support it, then probably Tumult and other web developers should stop too.