How do I fix blurry text when publishing project as HTML5 for an LMS? (see images below?)

Besides the null variable idea, the other solution is to publish with a larger-sized slide and turn on HTML Scaling when you publish. Your text that is converted to images will become larger and will impact your published project size. However, it saves you from having to adjust all your text objects in your project. Lately, I have been developing projects at a resolution of 1470 x 900 instead of 1024 x 627. If you think of the second number as the equivalent to TV resolutions, 900 is much closer to HD quality, and the 627 is much closer to old standard definition TV quality. Anyway, the results will speak for themselves. When you select HTML Scaling when you publish, the project will scale down for smaller browser sizes, so the increase in resolution should have minimal impact on your users (except for the improved quality of text and images).

Non-responsive project?  In that case text is not rendered on runtime but converted to images. That means that rescaling can lead to blurriness. You can insert an empty variable in each text, to get dynamic text which will be rendered on runtime, same as the system variables in a score slide.