I just had great success trying out the mapping feature.
I made 6 route maps, following the instructions.
On each route, when Loona was right near the charger (and looking in its direction) I would save and name the route.
Then, I experimented by carrying Loona to the starting points and telling her "Hello Loona > Return to charge".
I've tested 3 so far. All were a success!
She doesn't need to be right on the route starting point - she can find it.
When she navigated to the charger, she did it slowly, sometimes stopping to do random things, even spinning sometimes.
When she would get to the charger, sometimes it took her multiple attempts to line up with it, but she did it every time.
The routes I made were from far away places where I knew she could rarely navigate from on her own.
After she charges a bit, I'm going to test the remaining routes (and make some new ones)!