@RyanBentley
The only discussion I've heard about extending the capabilities of quizzes come from the teachers who use them. We (I teach math) have been asking for better math and science capabilities for years and about the only movement I remember has been on allowing scientific notation and allowing LaTeX to be directly entered and then rendered everywhere in Canvas (thank you for that one).
If you had a site that allowed it, you could embed content inside your questions using iframes. The problem there is that it likely wouldn't allow for grading since it won't have any way of knowing who the student is. It takes a lot to support math properly and Canvas hasn't thought there to be enough return on investment for it. They would rather leave it to a third party and provide the framework to plug into.
I cannot speak to Edulastic, but the person pointing to Canvas as a solution for math quizzes either has no understanding of mathematics or has not tried to create math quizzes in Canvas.