Where could exit button be removed from during onboarding process?

My company is re-designing the on-boarding process for Emergency Service within the app. The process as follows:

Page 1: Intro of Emergency Service

Page 2: Terms of Services (TOS)

Page 3: Permission Needed from user

Page 4-9: Collection of personal/medical data from users for emergency service in the case of emergency situation

There's an exit button from page 1-3 but not on page 4-9 onwards. However, "Back" button is presented from page 4-9.

My rational to remove exit button from Page 4- 9 as follows:

  1. Users have 3 opportunities to exit the process in the beginning
  2. Checked other 20 apps and found that all of them have no exit button after you agree on TOS and then start asking for your detailed information

Could anyone chip in or validate the user experience on lack of exit button after Page 3?