How to get into Windows 10 Safe Mode on 2016 MacBook Pro?
Microsoft changed how to get into Safe Mode on Windows 10. This assumes that Windows is your default startup disk. Basically hold the shift key while booting up or restarting. From Microsoft.com:


  Restart your PC. When you get to the sign-in screen, hold the Shift
  key down while you select Power Power icon 
  
  
    Restart. After your PC restarts to the Choose an option screen, select Troubleshoot > Advanced options > Startup Settings > Restart.
    After your PC restarts, you'll see a list of options. Select 4 or F4
    to start your PC in Safe Mode. Or if you'll need to use the Internet,
    select 5 or F5 for Safe Mode with Networking.