I know that MSDN has both retail & VL ISO. But no idea about tech branch. What is it for? Trial 30 day's copy or what?
I just completed a test on both MSDN and TECH BENCH isos by adding ei.cfg to the Sources folder to control what versions are installed. MSDN version of Windows 10 will accept ei.cfg and displays the selected version on installation. TECH BENCH version of Windows 10 failed to accept ei.cfg and did not allow control of version install. There MUST be something different between the TECH BENCH and MSDN Windows 10 iso files.