Pretty sure the "trivial" in the blog post is sarcastic, or at least slightly self depracating.
The "trivial" solution doesn't work. And they thus had to do the non -trivial thing and write their own custom text renderer. If I'm right in my reading, the author of the tweet is wrong to complain about them saying it's "trivial," because they never did.
Dear ImGUI also does this, and while font baking is not trivial, integrating ImGUI is almost.