TWOV exit Shenzhen by train?
Firstly, I successfully got into the country by showing a ferry ticket out of Shenzhen to Hong Kong. I originally had a train ticket but my arrival card asked me to choose as a port of exit either Shenzhen airport or Shenzhen ferry port (but not Shenzhen train station) so I panicked and bought the ferry ticket, and chose Shenzhen port as the point of exit.
I was wondering if I could still take the train, as it seems a lot easier and faster. Or is the train (as is suggested by the arrival card) not a valid exit? Or do they get weirded out if I take a different way out of the country than I said?