Here, I went ahead and wrote it up for you!
Add this as a component to your scene, drag in the SuperTextMesh object you're using, and then instead of calling Continue() on SuperTextMesh, call Continue() here! It'll still return false when there's no more text left to show.
I'm still trying to figure out the real solution to this... I might just implement code like this directly into STM or something, because this feels more reliable?