A note about AutoScaleAll. In previous versions AutoScaleAll always scaled the layouts based on the device physical size and the "standard variant" (320x480, scale = 1). It was only meaningful (per design) to call AutoScaleAll with the standard variant.
Starting from v3.20 AutoScaleAll works with other variants as well. For example if you create a tablet variant and then load it on a phone device then the views will become smaller. This is the correct behavior.