How Good Was Grigoryan’s Famalicao Open in 2019 (with a Perfect 9–0)?

I saw something on the Internet about this Famalicao Open from 2019, which Grigoryan got a perfect score. It was claimed that this was the greatest performance ever. Please, it was not. There have been quite a few perfect scores in chess history with stronger opposition than what Grigoryan faced. My rating system looks at all of this stuff because it was built be immune to the effects of rating inflation and deflation. This tournament that Grigoryan got his perfect score in was very large with a lot of players in it. It would take me an incredibly long time to input all of this data into my rating system. Because of time constraints, I just input Grigoryan’s games to be able to get his G-score. The ratings of the players he faced were Elo ratings, which could possibly be wrong. Nevertheless, it won’t affect his G-score much even if one of the players was off by even 100 points or so. Thus, I will accept these Elo ratings for the purposes of calculating Grigoryan’s G-score here. With these caveats, here is my report on this tournament and Grigoryan’s performance.

Famalicao_Open_2019
10
Elo
2549 Grigoryan
1537 Sousa
2087 Fidalgo
2376 Fernandez
2425 Damaso
2405 Cori_T.
2511 Spraggett
2497 Petkov
2511 Vassallo
2513 Galego
2800
2 1 0.0
1 3 1.0
4 1 0.0
1 5 1.0
6 1 0.0
1 7 1.0
8 1 0.0
1 9 1.0
10 1 0.0
-1 -1 -1.0