Software

I don't have the latest SMA 10.X version of KACE installed so I am not aware if the new Features Update can handle this. 

Last year (while running SMA 7.X) I did multiple in place upgrades from Windows 7 to Windows 10 Enterprise Version 1903 (32 & 64bit), which I believe will be fairly similar to your situation. All apps & documents were preserved.

Based off this blog post, an in place upgrade from LSTB/C to Enterprise CBB can be done. https://miketerrill.net/2016/01/11/windows-10-enterprise-ltsb-to-cbb/ 

I used a Managed Install based to get this done following this Quest Article https://support.quest.com/kace-systems-management-appliance/kb/255380/windows-10-build-upgrade-deployment-walkthrough 

To deploy I created a smart label and targeted certain machines on certain days between X hours of the night. 

In my case since I was going from Win7 to Win10 Enterprise I needed to enter a new license key then have my Managed Install use the following install option:

setup.exe /auto upgrade /quiet /pkey (licensekey here) /showoobe None /DynamicUpdate Disable /compat IgnoreWarning /CopyLogs C:\Temp\Logfiles.log

These will vary depending on your environment but things that I had to do after the upgrade was completed (did this in one script that would run on the nights I ran the deployments)
1. Import new Local GPO settings specific to Win10 Enterprise
2. Apply new registry settings 

My advice would be to test this out out manually on a test machine or vm first so that you can get an idea of how long the process will take and if there are any settings after the upgrade that need to be turned off/on ex Cortana. Hope this information helps to point you in the right direction and let me know if you have any additional questions!