One thing I like about the newer HHKB keyboards is that they're remappable, which somewhat addresses the Windows shortcomings. The remap tool is only officially supported on the more expensive wireless keyboard, but it works on the wired Classic model by editing the "KeyboardDatalist.json" file in the install directory and replacing all instances of "false" with "true". I mapped Fn+HJKL to the arrow keys, Fn+F to PgDn, Fn+B to PgUp, Fn+N to Home, and Fn+M to End.