The design was taken from here

1. In a screen with many textFields, a lazyColumn with imePadding modificator is not a good solution, because on lower textFields the keyboard appears for a second and then disappears. It is better described (here)[https://stackoverflow.com/questions/73438920/unable-use-a-textfield-at-the-bottom-of-the-screen-in-a-lazycolumn]
2. In signUp screen I use deprecated accompanist insets so that to make the textField scrolling and focusing to work as I intended. It is the actual problem of compose, more details here: https://issuetracker.google.com/issues/192043120 | https://issuetracker.google.com/issues/217770337
3. Interesting solution with states for textFields. You can take some inspiration from JetSurvey app.
4. I do not use BaseViewModel (though it is sometimes easier to create a base class), I try to use delegation
5. Useful articles on multiple back-stack in navigation component: 1, 2, 3