Sometimes you're on your way and auto zoom is perfect. Then you need to have a closer look, and zoom manually.

Doesn't work - you'll have to switch off auto-zoom before, otherwise zoomlevel switches back according to your speed.

Background of my idea:
I use Locus as a bike computer on a somewhat small Xperia active. Any need to call a menu to switch on/off a certain function causes me to stop, because the keys are to difficult to hit when driving.
Therefore I try to figure out repeating usage scenarios and try to automate them.