If you are working with MultiLang, then don't enable NetFX3 as part of an OSBuild Task, as that will not have all the language support that you need and you will need to reinstall the LCU
Windows 10 1909 uses the same FOD as Windows 10 1903
New-OSDBuilderContentPack
Start by creating a new ContentPack with the following command
New-OSDBuilderContentPack -Name "MultiLang FOD NetFx3" -ContentType OS
Remove Unnecessary Content
You can now safely remove all directories in the ContentPack except for OSCapability
In the OSCapability directory, remove the ones for RSAT
Create directories as needed following the example directories
Copy Features on Demand
Mount the Features on Demand ISO and copy the metadata directory and the FoDMetadata_Client.cab
Now copy all of the NetFx3 files that you need, making sure to include the Language Neutral one (highlighted below). You can clean this up if you prefer, or leave everything in there (they are not taking much space anyway)
You can add repeat this process for all your Operating Systems
New-OSBuildTask
Now simply add the ContentPack to your MultiLang OSBuild Task with the AddContentPacks parameter, and don't use the EnableNetFX3 parameter. During New-OSBuild, NetFX3 will be enabled with the proper Language support
