Interesting - it didn’t for me? I turned it mobile data to everything else to nothing was chewing it up in the background.
We’d previously done the load up on Wi-Fi then follow the blue dot, but the ability to change route cause traffic (M25!!!) or detour cause something looked interesting was fab.
I’ve kept mine on all the time this last week, as I won’t get near 4GB with my phone on low battery mode, as staying charged has been a bigger issue now we aren’t in a car (which is prob the age of my phone).
Love it!