I went back from Windows 10 Pro to Windows 8.1 Pro with WMC, I got an ESD of IR5, then decrypted to create an install .iso and added the following:
Enabled dotnet 3.5
Slipstreamed dotnet 4.6.2
Slipstreamed Windows Update Client for Windows 8.1: March 2016
Slipstreamed Servicing stack update for...