Is the ruling on doubting the start of the Sa'y from Al-Marwa the same as the ruling on doubting the number of circuits of the Sa'y, along with the legal derivation in the Shafi'i school of thought?

If, during Sa'y, the performer doubts whether he started from Safa or Marwa, he should consider that he started from Marwa and add an extra circuit to clear his conscience with certainty. This is based on the principle of building upon certainty, which is the lesser (number of circuits) when in doubt during an act of worship. However, if the doubt occurs after completing the Sa'y, it should be disregarded.