One (a bit more powerful) way to achieve similar results might be implementing mapsets i.e. allow creation of multiple configurations of base+overlay maps and assign name to them.
Then allow putting buttons activating given mapset directly on the toolbar.
Ideally with button "Swap last 2 mapsets".
Then allow putting buttons activating given mapset directly on the toolbar.
Ideally with button "Swap last 2 mapsets".