This new version of Shotcut adds partial support for VST2 plugins
While there is a way to exit safe mode (no external plugins), there is no way to enter it manually from the UI. I will add that for the next version. In the meantime, here is a partial workaround:
Do you know how to set an environment variable on Windows that is not system-wide? You would open Windows cmd.exe and enter set VST_PATH=no. Then, cd to where shotcut.exe is and run shotcut. Next, run the same export that previously hung. That would help us determine if that is related to the problem.