From the navigation apps out there, I have compared Pocket Earth against Apple Maps, Google Maps, Navfree and Sygic. From these, Pocket Earth has the best visibility (see picture attached). I took the app out for a ride today again, and used a somewhat more zoomed in view. In practice the b-roads are never dead ends; I have taken comfort in not seeing where the road connects back to another road – as long as I have north up I know where I am going! With a slightly more zoomed in view the map is in practice sufficiently readable on the bike – consider the feature request withdrawn (although it would still be a cool option to have a high-contrast Map Style).
I did not have trouble locating my present position on screen, probably because on an iphone you have a lot less screen area to scan than on an ipad.