In the default main.sublime-menu file, the “Word Wrap” menu item has a “mnemonic” value of “w”. However, hitting “alt+v”, followed by “w” doesn’t toggle word wrap.
Conversely, the “Ling Endings” submenu has a mnemonic of “n”, and hitting “alt+v” followed by “n” does indeed bring up the submenu.
Do mnemonics not work for activating commands in menus?