Running Leap_Motion_Orion_Setup_win_3.2.0.exe /S works for me. I can see the process throughout its run in Task Manager as well as the file changes in C:\Program Files (x86)\Leap Motion
The only gotcha that I initially encountered was that I had to make sure I ran from an Administrator command prompt. Without elevated privileges, the silent install would terminate immediately. Let us know if it's still failing in this case.
If you later opt for manually installing the extracted files, that might be reasonable with Orion. You run LeapSvc.exe --install to install it as a Windows service, but our software can also be run in user mode via LeapSvc.exe --run as well. Orion has fewer special steps compared to V2. For instance there is no longer an INF driver installation, and if you're not using WebSocket you can disregard the TLS certificate part. Automatic updates for future releases, desktop + start menu shortcuts would be missing so it depends on whether that functionality matters to you.