Hello Leon,

I havent found a way to do a downgrade on Zebra devices with Soti Script alone, you have to use Zebra MX for this and call the XML file with the Soti Script command "mxconfig"

The content of the xml file (created with Zebra StageNow tool)

<wap-provisioningdoc>
<characteristic version="9.2" type="PowerMgr">
<parm name="ResetAction" value="11" />
<characteristic type="file-details">
<parm name="ZipFile" value="/sdcard/OSFile.zip" />
</characteristic>
</characteristic>
</wap-provisioningdoc>

greetings
Martin

Confirming what Martin has said. You can't use the typical install_system_update script because it is a downgrade operation. The MX path does work, however you may run into a Factory Reset scenario by going through with this method. Note also that some Helios devices like the WT6300 and MC3300x will not support downgrades to 8.1 from Android 10. Future BSPs may also not support downgrades if there are any component changes to the MC9300. 

Thank you Matt for mentioning the issue with the Enterprise Reset, this will be executed by the Zebra Device after each downgrade, independed if just a lifeguard downgrade or complete OS downgrade from 10 to 8.

I already managed to get the Zebra devices itself back into MobiControl after a downgrade and forced enterprise reset if I set the WLAN profile persistent with help of MX.

Thanks for your answer Martin :) 

Just a question about my understanding. 
If I do a Downgrade from Android 10 to 8.1 it is still registered in MobiControl right? 

I did the same procedure with ADB sideload but at that point it wasn´t enrolled in MobiControl. 

Edit: If I tick this option in the advanced settings of the enrollment rule the device should be reenrolled automatically??