Offline is fine - you plot a route then download. Keeps the map tiles on the phone. If you can't be bothered to plot a proper route, just draw a line through all the areas you're likely to need. Not elegant but gives a full offline map.
Alternatively, buy a map and enter the map reference to download the entire map.
Zoom is fixed too - just change the layer from automatic to 1:25000.
Only area that badly need improvement is 'favourites'. Not possible to group in any way so have to scroll through a massive list of routes to find the one you're looking for.
Best £20 a year I spend.