I am learning and getting way better in animating and a few other stuff (shading, writing, etc...) as the game progresses.
When I've reached a certain skill cap, a few animations then become garbage because the global quality stepped up. Just compare Elise Facefuck at school with Sarah anal at home, this is day and night.
I am also making sure to improve the writing so one character doesn't get stuck in a loop, which was the case for the previous Sarah, hence the rework of Sarah which is objectively one of my best works if you look at the writing, pace, and animations.
So I strongly disagree regarding the rework topic, I consider I am bringing a great balance so one character doesn't feel completely trash with bad animations compared to the others.
But well, I respect your opinion.
People have deleted their v1.3 app when they played the v1.4 two weeks ago, and they kept their saves.
So you shouldn't lose your save when deleting the v1.4 and installing the v1.5 unless your Android behave differently than the others.