Yeah the entire concept of how font size might relate to Planck volumes is pretty funny to me. It’s not possible in any way, so people getting caught up on the semantics is just funny. Like, if you can write the letters in “trillion” at a size where one letter is the size of one Planck volume, then you’re already somehow etching lines that are smaller than a Planck. In Wit hout higher-than-Planck resolution you wouldn’t be able to write any fonts at that scale. It would be like trying to write on grains of rice with a pen tip larger than a grain of rice. Easy to make a mark, difficult to write characters.
I think the metaphor about how big it would be if you wrote it out isn’t about maximizing font density, but rather about trying to put it into some kind of terms that people might understand relative to their daily lives. The formulation I first came across was based loosely on the number of characters that fits in an average book. This gives you a mechanism for imagining the data as a stack of books. So, if it were actually written out, not at a Planck scale, but a human scale, it would be about so big. This ”hardcover” model doesn’t work so well for super huge numbers because it’s just way more matter than we think exists. It does not make it easier to comprehend.
But you could imagine this “printed mass” might be an interesting way to envision some number or dataset, if it was say, the mass of the moon, or I dunno, an elephant.