@WorkerThread private static void startProfileOwnerPostProvisioning(final Context context, final DevicePolicies policies) {
		final boolean owner = Users.isOwner();
		startDeviceAndProfileOwnerSharedPostProvisioning(context, policies);

		IslandManager.ensureLegacyInstallNonMarketAppAllowed(context, policies);

		// Acquire SYSTEM_ALERT_WINDOW permission to overcome "background activity start" blocking on Android Q+.
		if (SDK_INT > P && ! Settings.canDrawOverlays(context))
			new AppOpsCompat(context).setMode(AppOpsCompat.OP_SYSTEM_ALERT_WINDOW, Process.myUid(), context.getPackageName(), MODE_ALLOWED);

		if (SDK_INT >= Q) policies.execute(DevicePolicyManager::setCrossProfileCalendarPackages, null);

		// Some Samsung devices default to restrict all 3rd-party cross-profile services (IMEs, accessibility and etc).
		policies.execute(DevicePolicyManager::setPermittedInputMethods, null);
		policies.execute(DevicePolicyManager::setPermittedAccessibilityServices, null);
		if (SDK_INT >= O) policies.invoke(DevicePolicyManager::setPermittedCrossProfileNotificationListeners, null);

		if (! owner) startProfileOwnerPostProvisioningForNonOwnerProfile(context, policies);
	}
All the preparations after the provisioning procedure of system ManagedProvisioning, also shared by manual and incremental provisioning.
engine/src/main/java/com/oasisfeng/island/provisioning/IslandProvisioning.java