Opening New Hotbars...

[MarkSam]

In an emergency you can open a hotbar with the text command:

/open_next_hotbar

Closing hotbars is tougher, but it has a text command too.

/close_hotbar [x]

...where [x] is a zero-based number, one less than the hotbar number. Sort of...

The hotbars are numbered when they are opened, and keep that number even if you change the bar with the spinner. So if you /open_new_hotbar with six bars open already, the newly opened seventh hotbar can be closed with /close_hotbar 6. If you change it to a different number with the spinner, its still the same number to close it.