This is a message added to a ScrollingMessageFrame in InsertMode 2, so starting at the bottom. Is there a way to bump it up a few pixels, so those specific letters don't get cut off by the frame's edge? Moving/resizing the frame will cause the fontstrings to "jump" a pixel up and down, as it likes to do, so it is possible to get it to display perfectly, but I'd like to avoid the occasional glitch.
I found a solution, for anyone running into the same issue. The ScrollingMessageFrame keeps an indexed table of visible lines, called visibleLines, where 1 (at least in my case, with insertMode 2) is the first one, and RefreshLayout gets called every time the frame gets resized, moved, etc.