Resizing Text to Maintain WCAG 2.0 AA compliance?

We've been working with an outside vendor specialized in auditing online content to ensure WCAG compliance and screen reader usability. We're trying to make WCAG 2.0 AA compliant content.

While there are many aspects outside our immediate control that keep causing issues (such as poor ARIA labels and poor SVG output), one factor that keeps coming up is that the text cannot be resized 200% with relative sizing. The only option is to zoom with one's browser, which is absolute sizing and is therefore NOT compliant.

Has anyone found any workaround for this (such as adjusting the code output in the zipped file itself)? All of the content I can find in the Storyline-provided documentation says it is "user controlled" and that users can "zoom with their browser" so I'm at a loss.