Reading order using a screen reader of control buttons doesn't make sense without a visual representation. The "move up" and "move down" buttons are divorced from the list-select box. The buttons precede the "My Active Sites" heading and subsequent text and "Tabs displayed:" prompt and text-entry box?then you get to the list-select box.
Likewise, "move selected" and "move all" are separated from the Hidden list-select box by the "My Hidden Sites" heading and the following text.
Solution (note: I am using the suggested alt text language requested in issue #
Change the reading order so that the controls for a list-select box directly follow that list box.
After "My Active Sites", place the following buttons:
"move selected site up in list"
"move selected site down in list"
"hide selected site"
"hide all sites"
After "My Hidden Sites", place the following buttons:
"make selected site visible"
"make all sites visible"