I found a problem with abnormal large size of satellite maps.
1. download a topo map
2. add a satellite layer, at that time it has normal size
3. add a topo pro layer
4. voilá, the satellite map is now 3.7 million GB large :)
In this example it is a less painful problem. When you delete the satellite map and reload it, the problem vanished (for the moment ?). I had more problems with this. Sometime the download stuck because of the seemingly large file. Sometime the complete set of maps and layers for an area had to be deleted. So far I could only reproduce this little problem. But there is some larger behind.