A cool thing about using WSUS Catalogs is the ability to download Feature Updates. These updates are used by WSUS to upgrade Windows 10. These files are in ESD format and must be converted to WIM for Offline Servicing. Keep in mind these Feature Updates are Volume License media, so this won't work if you use an OEM, Retail, or MSDN product key.
OSDBuilder can download the Windows 10 Feature Updates and convert them automatically to WIM
To view and Download the available Feature Updates, use the following command
OSDBuilder -Download FeatureUpdates
You will see that there are two different types per language available (Business and Consumer) so make sure you pick the right one. Select the ESD file(s) you want to Download and Build and press OK
After pressing OK, the Feature Update will download using to OSDBuilder\Media using BITS Transfer. The nice thing about BITS Transfer is that you do get to see progress of the download
An ESD file contains several Indexes, just like a WIM. The next process is to rebuild the ESD file into a proper Windows Media format. This involves expanding the Windows Setup Media (Index 1), the Boot.wim (Index 2-3), and the Windows Images (remaining indexes). This process will take some time as it must be converted from Recovery compression, to High compression (about 10 minutes)
Import-OSMedia can now be used to import the Feature Update into OSDBuilder where it can be Updated and Customized just like any other OS
Yes, I know what you are thinking ... Can you copy your own extracted ISO into the OSDBuilder\Media directory and import the OS?
Yes you can ... but keep in mind OSDBuilder is not meant to service customized Media ... don't bug me for help on this if you decide to go this path