This has actuallly been answered for over 1000 times, since MSFT started to release fake new builds (1909 and 19042/3) only to keep their 2 releases per year policy. The EP releases are just registry only and only mounting the image and running a dism query will show the image version 19042 or 3.
That's what I figured it was (small) but after the CU the Disk Cleanup of mostly the 'Windows Update Cleanup' was 4.29GB.
I did a clean install of the Techbench ISO 19043.928 and one of the packages is listed as: Package_for_DotNetRollup~31bf3856ad364e35~amd64~~10.0.4340.4 What KB is associated with DotNet version 10.0.4340.4? KB4586876-x64-NDP48=10.0.4300.1 KB4598299-x64-NDP48=10.0.4320.1 KB4601050-x64-NDP48=10.0.4330.6 KB???????-X64-NDP48=10.0.4340.4 <--What KB goes here? KB4601554-x64-NDP48=10.0.4341.2 KB5003254-x64-NDP48=10.0.4360.1 EDIT: Even when KB5003254 is installed, v10.0.4340.4 shows as a base package: Package_for_DotNetRollup~31bf3856ad364e35~amd64~~10.0.4340.4 | Superseded | Update | 4/9/2021 1:44 PM Package_for_DotNetRollup~31bf3856ad364e35~amd64~~10.0.4360.1 | Installed | Update | 5/25/2021 10:12 PM