Individual science exposures within each Observing Block (OB - field/fibre configuration) will include calibration and flatfield exposures that will be read with fast readout mode (20 seconds), whereas the sicence exposure readout will be normal (98 seconds full frame, unbinned). The estimated overhead time per science readout + calibration + flatfielding is 2 minutes. Additionally, the field acquisition overheads of the new OB (approx. 1 minute) can’t be hidden in the read-out time of the exposures of the last OB, but efforts are being made to optimise this transition between consecutive OBs.