This looks like it may be an X bug.
/etc/default/console-setup ends up with the correct options: XKBMODEL="pc105" XKBLAYOUT="us" XKBVARIANT="dvorak" XKBOPTIONS="lv3:ralt_switch"
Which X gets: (II) XINPUT: Adding extended input device "AT Translated Set 2 keyboard" (type: KEYBOARD) (**) Option "xkb_rules" "evdev" (**) Option "xkb_model" "pc105" (**) Option "xkb_layout" "us" (**) Option "xkb_variant" "dvorak" (**) Option "xkb_options" "lv3:ralt_switch"
This looks like it may be an X bug.
/etc/default/ console- setup ends up with the correct options: "lv3:ralt_ switch"
XKBMODEL="pc105"
XKBLAYOUT="us"
XKBVARIANT="dvorak"
XKBOPTIONS=
Which X gets:
(II) XINPUT: Adding extended input device "AT Translated Set 2 keyboard" (type: KEYBOARD)
(**) Option "xkb_rules" "evdev"
(**) Option "xkb_model" "pc105"
(**) Option "xkb_layout" "us"
(**) Option "xkb_variant" "dvorak"
(**) Option "xkb_options" "lv3:ralt_switch"