Another thread, which I found on the Search function, is titled “What determines how many lines I see when I hold my mouse over a thread title?” That thread explains that the number of lines is controlled by which browser one is using.
This is a related question, and I would have put it there, but that thread is over a year old already, so here goes:
I really like that mouse-over function, and I’d love to have it show me more lines, but alas, that other thread says I can’t adjust that. But how about the length of time that it remains on-screen? Most of the time, it goes away before I’m done reading it. Is there a way to make it stay longer?