My very old Lowrance 1000 and 2000 divide the screen into two selectable zoom levels so I never had to fuss with anything. Those gps are no longer available or serviceable and I've gone through 3 of them. iFly has the most desirable features and in some cases better than those old units because they give an ETE: waypoint readout down to the second.
Most of my flying is with the screen at 0.2mi wide with a complete new screen coming into view every 10 to 11 seconds. I zoom out to 2 mi wide at the end of each flight line (say every 1 to 4 minutes) depending on the area covered. I am having to make flight corrections at least every once a second to maintain accurate flight lines. There is a great difference correcting flight from a screen that's at 2 miles wide vs the 0.5 mi. wide screen I need to fly by. I make do with out the tool now but other areas of flight could use the attention. You never know unless you ask.