Delta updates for Server 2016 from SCCM SUP

Hi All

I haven't been able to find anything definitive about delta updates for server 2016 from SCCM 1706. The Docs page on Express Update delivery only talks about Express being supported on standalone WSUS, but there are tick boxes for Express for Windows 10 in the SCCM console. 

I haven't been able to get delta updates for 2016 downloaded. Any advice?