Level 1 (This is just starting, no closing and opening the app nor making an account, those also change stuff.
This last one I did play a few turns so it did start at 15.
So ya if you close and open the app and/or make an account you will change the generation if you have not played a level. My last test game shows this nicely.
Might want to reduce the number of variations there King LMAO.