hi, it will be great to add this shortcut as i use classic single most of the time with preview (alt+p) that opens on the right pane, but use dual mode sometimes. it's always good to have a choice depending on the need.
when i use vertical (standard) dual layout for organising files, the preview becomes at the bottom and too small for PDF even after pressing alt+g to close the other column
i know i can use spacebar to open a preview window, but the focus is taken to the preview window preventing the use of keyboard to view other files (seems like this was just fixed in version 3.104)
or i can also use the horizontal dual layout, where the preview pane ie is on the right, but i like the vertical or single layout more.
if there are more layouts in the future maybe the shortcut can be made to be 2 steps, like alt+w, 1 for classic; alt+w, 2, for dual vertical; and so on.
and maybe
alt+w, w to toggle with the last mode.