From A10 to A11, you can use filesync and install_system_update without data loss.

I don't remember from A8 to A11. However, if you plan to update to A13, check this: https://supportcommunity.zebra.com/s/article/000027787?language=en_US

Hi Andy,

you can also use the "ZEBA FOTA" for updating the Devices.

But for that you need to Prepaire your System!

https://www.soti.net/mc/help/v15.6/en/console/reference/dialogs/globalsettings/zebra_lifeguard_ota.html

I would recommand Version 15.6.6 or 2024.1.0 there was it working perfect.

Whe you are using that ZEBA FOTA - all Devices needs the Contract per S/N that they are allowed to get Android Updates.

What i know ans experienced is that you can Upgrade from A8 or A10 directly with a Full Package to A11.

You can use the Suggested Solution from Alin - what is also working.

Or you create a Profile what is checking the "OEM Version" in MobiControl what Package needs to be installed on the Device. (i only Replace the zip files on FTP Server (TC52-A11.zip - full Package or TC52-A11-Inc.zip for incremental) and adjust the Filter in the MC Package)

The ZIP Packages will be downloaded form an FTP Server in the cloud to have the best Performance at all locations. Then it will be installed and the Device is updated.

Second i have some virutal Groups in MobiControl to see in one view which Devices had not been updated actually and can "reinstall" the package to start the Upgrade again manually.

I prefere the Option with Package and FTP Server - here i can choose what Version should be rolled out.

When you get Device with A13 and downgrade it to A11 you can use the Downgrade Profile form Stage to create a Profile that it will downgrade it automated.

Theoretically you should be able to go from A8 to A11 directly with an A11 FPU Zip file delivered via File Sync Rules. I like targeting File Sync rules at VGs for OS Updating Zebra devices as you can have filtered sub VGs under a parent unfiltered VG that can help you automate the process of upgrading the devices. I don't like Package based delivery of OS updates or relying on an external FTP server as the File Sync rule process is more resilient at handling network connectivity and other device availability interruptions. 

As with anything you shouldnt just take our word for it. You should test the process on isolated devices going from A8 to A11 and observe the behaviors throughout. IIRC I've had to have an additional reboot added to the process when jumping from A8 to A11. It has been a while though as I'm taking most of my environments from A11 to A13 right now and haven't had to upgrade an A8 device in a couple of years. 

On the topic of not wanting to Factory Reset your devices, the A11 to A13 upgrade of a Zebra Helios family device like the MC9300 will result in an Enterprise Reset. It's not a full Factory Reset but it will wipe most of your applications and configurations. Thankfully the SOTI agent is enterprise reset persistent so as long as you also make your network connectivity enterprise reset persistent before your upgrade you can upgrade your devices from A11 to A13 without any manual intervention. SOTI will reinstall all the Profiles and payloads after the devices reconnect post upgrade. Any apps that rely on local app cache will be wiped in the process but its otherwise a relatively smooth process jumping to A13.