When you have a long page name and use the "icon" menu type, ellipses are automatically added to page names that are too long to fit into the non-resizable window:

However, when you use the "vertical" or "horizontal" menu types and you run out of area, there are no ellipses:

^ Vertical (this one is also missing the "HAA5" and "TTHM" folder expand/collapse arrows due to the length of the bottom page name)

^ Horizontal
I know I shouldn't be making page names this long--these are mostly an exaggeration--but I can see getting pushback on some of the stuff I'm doing currently, like using abbreviations, acronyms, etc. to cut down on characters. As you can see with the "vertical" example, there can also be consequences for other pages, like losing the expand/collapse arrows. Ultimately, I can only do what the software will allow me to do, but ellipses would certainly look better than just having text get cut off.