Hi Nico,

You may mix what split means is wsjt-x. It does not mean that you are using different reception and transmission frequencies. Actually that setting is totally independent of that “split frequency” usage on band.
It only means how transmitter frequency is generated. Both Fake It and Rig methods keep transmitter *audio* frequency in range 1500 – 2000 Hz. In the Fake It method rig VFO is tuned to compensate the audio frequency change. In the Rig method two VFOs are used i.e. RX VFO is kept on the reception frequency and TX VFO is moved as needed for compensation.
For “band frequency split” you set RX and TX audio frequencies on different spots and the above happens independently of it pending only on the TX frequency.

73, Reino