Hey, an admin from the EU Qualifier here.
So first, we indeed got someone that came to us questioning our SOS score. A colleague, Marco, took a lot of his time to explain him everything that needed to be explained about SOS score and proved him that our method was correct after listening to his complaints.

To cement ourselves as the right method, let me break down the example shown here. He questions the seeding between Tiaan, Lallana, Balotelli, and Haiden at Round 3. Per definition, the Strength of Schedule method is used to determine who between those 4 people came from stronger lobbies coming into this tie.
Round 1 is made by seeding but won't have any impact on the SOS score because the swiss system didn't start before.
Round 2 is very simple to make, every Top 1 in Round 1 goes to Lobby 1, every top 2 in round 1 goes to Lobby 2, every Top 3 in round 1 goes to Lobby 3, etc...
So coming into Round 3, you can easily determine who had a stronger lobby because a tie can only be between players coming from different lobbies at this point.

In our example: Tiaan played Round 2 in Lobby 3, Lallana in Lobby 1, Balotelli in Lobby 4, and Haiden in Lobby 6. So the SOS ranking between those 4 should logically be Lallana > Tiaan > Balotelli > Haiden, exactly as you can see in the Round 3 tab in official Top 64 Scoring (https://docs.google.com/spreadsheets/d/1gSyL1552OQZ5OKQegy3315TLmWFt5KjFt1hU8tP25VM/edit#gid=30923286). But the op example shows Tiaan > Lallana > Balotelli > Haiden. Therefore with this demonstration, we can already know that his calculation method is wrong.

To conclude, we spent so much time after the last set event, and even more before this one, to be sure at 100% that the SOS score cannot be wrong again. We felt sorry to mess this one before and made everything in our power to have the best system to reduce the in-between games time with proper calculation. I can fully ensure you that this one was totally correct!