If the bed levelling isn't live that's probably why they force the massive raft. That's disappointing.

When you say bed calibration do you mean Z-gap adjustment?

Bed levelling (compensation) - touch off on several points and calculate the skew of the bed relative to the gantry, and adjust Z actively while the head moves across each layer to compensate for the hardware misalignment.
Z-gap adjustment - setting the offset from the extruder tip to the bed. If it is out by much more than 0.1 mm you will get a bad start to the print (either too high or too low - nozzle scraping across the BuildTak).