Don't forget your user that has some disabilities, they must also be able to use your website and your menu. Maximenu CK offers an option to give an access key on each menu item.
Using the Maximenu CK Pro you can edit any menu item and write a key that will be used for accessibility. For example, if you want to give the letter "q" you can write it directly in the option :
This menu item will automatically have the attribute "accesskey" with the value "q". This is easy to do, but can be very important to have for some people.