Just an FYI here, my github
will have the latest up to date scripts, so treat this thread as an "archive" of the older version.
But to your question...
So the answer is... sort of. You can't have completely dynamic fonts, each font needs to have its own fonts table entry. That's why in version 1.3beta (in the github right now), it's set up for multiple resolution ranges with some specified font. So you could
make something where it sees it has just one line and picks the "larger font".
Might be a good first project for someone to tinker with.
gr.drawString will return the number of lines, so you could have the script start trying fonts and figure out how best they would fit.