Accessibility in Twine

Note: I’m using Twine 2 Harlowe specifically.

I know that at the moment screen readers don’t work with Twine, but I want to design my game with accessibility in mind in other ways, if possible. I already plan to include a high-contrast color palette and include alt-text in any images, but are there other moderately easy to implement features that I could include in order to make it as playable as possible?

Not sure how easy it would be to allow readers to adjust font size- do you think that’d be possible? The standard stuff (as applied to text) usually includes not using colours as the sole way of displaying information.