I use the PortableApps Platform since years and since years mostly with the keyboard.
Since ever I can remember, the menus and the context menus open, if initiated with the keyboard, at the position of the mouse pointer, not at the position of a list item of the apps list, not at the position of the "Apps", "Backup", "Options", etc. "menu buttons".
Please consider to change the position of the menus opened using the keyboard, to be context, not mouse pointer related.
Thanks in advance!