An alternative for now:
Set everything up how you like it. Then, goto the URL opera://configure/mods, hover over the center Opera icon on the page and click the "Set image" icon and pick an image. Then, hover over the new image that's now in the center of the page and click the "save preset" button.
You'll then see your new preset in the preset section on the page (along with the 2 default ones). Then, if you ever need to switch back, just click that preset. You can also switch presets in the Easy Setup menu.
