It was similar for us. However, an approximate site plan was already established beforehand, based on which we selected our plot. The entire construction area still had to be surveyed and several plots had to be merged into one overall plot. Parallel to this, buildings were demolished, the area was developed, the plots were filled, and then the individual plots were surveyed. Only after that could the soil report be done, while the notarized contract was about 6 months earlier.
There were small deviations due to the widening of the road compared to the planned street, so that our plot became about 15m² smaller than planned. This then had to be notarized again for us.
It was somewhat more problematic for those who had to finance the plot, since the land charge had to be registered on the entire plot first and then only after division was allocated to the individual plots. (Purchase price payment was before division)