I think this is separate from the locking the map in rotation mode Nic. I'd mentioned a while back that one of the features I liked about the Classic app that Cachly doesn't have is the "auto zoom". So that as you move the map zooms so as always to keep the current position and the target on screen.
This is particularly useful when you have phone in a holder on dashboard of car and you are driving to a cache location to park up. At present when you get closer the map doesn't change at all other than the option to rotate. This means that it is at one zoom scale - when driving often this is a few miles out but when you are in the last few hundred yards to parking its REALLY handy for it to show it at a far more detailed scale as at the scale you started out at the dots are basically overlapping, so what you want is to zoom in. Doing this manually means taking your hands off the wheel to fiddle with phone which is inadvisable. On the classic app it would zoom as you moved so that as you got closer it was very easy to see and so safer whilst driving.
Of course it is useful when on a lengthy walk too as you focus in on the area you want to search.