Yes, it acts as a client but it's still server. gailium119 also made one which he posted at bbs.pcbeta.cn It would be nice if gailium119 can help us
This is just EnterpriseS 20348.1 added to Server 20348.1. EnterpriseS 20348.1 has NOT been updated at all, Only Server packages have been updated. * Microsoft-Windows-EnterpriseSEdition~10.0.20348.1.mum Microsoft-Windows-EditionSpecific-EnterpriseS-Package Microsoft-Windows-Client-Desktop-Required-Package Microsoft-Windows-Client-Desktop-Required-WOW64-Package Microsoft-Windows-Client-Features-Package Microsoft-Windows-Client-Features-WOW64-Package Microsoft-Windows-EditionPack-Professional-Package Microsoft-Windows-EditionPack-Professional-WOW64-Package Microsoft-Windows-Common-RegulatedPackages-Package Microsoft-Windows-Common-RegulatedPackages-WOW64-Package Microsoft-Windows-Required-ShellExperiences-Desktop-Package Microsoft-Windows-Required-ShellExperiences-Desktop-WOW64-Package * Package NOT installed or removed after Microsoft-Windows-EnterpriseSEdition was added. Microsoft-Windows-EditionPack-Professional-Package Microsoft-Windows-EditionPack-Professional-WOW64-Package Microsoft-Windows-Required-ShellExperiences-Desktop-WOW64-Package * Better to make EnterpriseS 20348.1 on it's own "without Server" as updates "DON'T WORK FOR" EnterpriseS 20348.1.
Client can't be updated as there is no client packages in "Server" .cab or .msu to make a custom update, as you yourself have already said...
I agree - it's the server packages that are updated only. What's remarkable is what registry keys have been added for dism to upgrade only the server side of it and by extension be applied to all server versions