Can we have bigger fonts for text in DTG?

This was also bothering me. The solution that worked best for me as far as the display goes was HMTL:
<span style="font-size:2em;">Text</span> for text 2x as large
<span style="font-size:1.5em;">Text</span> for text 1.5x as large
<span style="font-size:0.5em;">Text</span> for text half as large
The font size increase in DT Preferences was only showing up in edit mode, not display. For headers specifically, Markdown’s system of hashes # text (or ## and ###) suffices.