Unreal Engine 4 is available for Win10 UWP app dev now

I see so I can create a save game using this. I asked about this because my previous engine was GMS2 and the UWP support there is 0 literally. To create a save system there people need to create buffers but the poor documentation there just don´t work . But its possible to test a saved game in dev mode XB1 ? If I save the game there, delete the package and upload again will I still be able to load the game or the save data will be lost ?