It’s a request for help, but no proposed solutions. This sort of thing happens constantly, and the size of the popover field makes editing quite difficult:
I don’t know what to suggest, except that any future improvements to this functionality would be immensely welcome!
I would certainly find an improvement here welcome as well. I can think of a few options:
I find that if I have to go back and edit something in a long string of text (just as you’ve shown) that I often overshoot one way or the other because you can’t see very far ahead, this is particularly true if you want to edit the beginning of the phrase. Clicking on the correct spot always starts you at the end of the phrase. It’s true that you can click on the previous lyric and then advance to the ext rhythmic position, but sometimes that’s awkward.
Use the Lyric Window instead? (I have Command L set up for that.)