I was actually concerned with the custom character sheet and number of shown lines, which is not the same as how much of the code is on each line. On my computer, in my browser, the html pane of the character sheet starts bogging down around the 7,000 line mark, and as I get closer to the 10,000 mark new lines do not always appear (especially when I cut and paste several lines of code), which, at least visually, result is lost of whatever it was I was writing. Since the whole thing is done on a browser communicating with the Roll20 site and back again, internet connection can be a harsh master with it. Now, actually using the character sheet in game...that's discussed in other threads.