Just to make sure how it's supposed to work:
The installer app installs the system files and checks the connection. This fails because of "access denied". The installer app tries to fix that, this also fails, and the app shows a button to enable the test mode and reboot the phone.
After reboot restart the installer app. Now there are two possibilities: the "access denied" is fixed and you are requested to disable the test mode and reboot, or the app retries SIM access, fails again and again prompts you to enable test mode. If the second happens, there is currently no way to enable rSAP.