The kill_application script that would have previously worked in this situation unfortunately does not work for Zebra devices under Android Enterprise management in SOTI.

For a moment I was thinking an alternative could be a shortcut to an mxconfig script that would kill the application for you but in looking at the MX options there doesn't seem to be a close application option.

An alternative to a script could be switching from the Activity Suppression based lockdown to the Native Kiosk and then enabling the Recents / App Switcher option so that you can give the user the access to kill the application manually themselves.

Note that access to the Recents button in the Native Kiosk is a function of Android 9 and higher so you would potentially have to upgrade your MC9300s to Android 10 in order to access this capability. I just tried it on an Android 8 TC52 (same Helios family as MC9300), and the Recents button was not shown on the lockdown of the device despite it being configured in the Profile. After upgrading the device to Android 10 the option appeared and I was able to manually close out apps while still in lockdown.   

I take it the "recent's" button is the bottom square on your picture

one thing i don't like about the "native" is the staus bar doesn't show, I like that for the battery and the wifi signal status

i set that up and you described and don't show the "recent's button on the bottom

next question is how difficult is it to upgrade to Android 10, this may be a Zebra question

we really need for the user to be able to close the browser when something goes wrong even though it's locked down

The first thing you'll need to do is get the devices on A10. You can use a File Sync Rule in SOTI to deliver the .ZIP file to the devices and then execute it automatically with an install_system_update script. 

The Native Kiosk has a lot of configurability once you get your MC9300 devices to A10. 

You can turn System Information On for instance:

I haven't tried this yet but it looks like a solution if our current setup starts to become a problem

thanks for the information

On my side, the Native Lockdown settings with the Recents Button does exactly what I want.  I have Zebra TC52AX on version 11. But I also have the Workstation Connect cradle.  But with this solution, the cradle does not recognize the external monitor.  The screen stays black.  On the other hand, if i use the Activity Suppression option, everything works fine with the cradle. But I've lost the Recents Button option.  Any solution?  I really need the option to "kill" applications.