Just a comment or two about courtesy deck checks, to add to what Riccardo already said.
The idea of checking all Top 8 decks at the end of the Swiss, prior to the Top 8, is a very old practice; it used to be a “Best Practice”, and I remember learning it over 15 years ago. The name “Courtesy Deck Checks” is newer - I first heard that term at an early
StarCityGames.com Open, back when they were called “5K” events.
It really was a courtesy - to each of the other 7 players - to have each Top 8 deck verified. However, the downsides have convinced me, and many others, to stop this practice. One huge downside is having a Top 8 match start with game 2, due to a Game Loss; it's rare, but there have been - prior to recent IPG changes - Top 8 matches that started in game 3, with each player having “earned” a Game Loss.
Another downside is the amount of time lost to track down all 8 players and their decks, and to check them.
Did they accomplish the goal? No, not always. I recall a State Championship, where a player had sideboard
Scavenger Folk, right after 5th Edition had rotated out of Standard. He was deck checked during the Swiss, and again as part of the Top 8 deck checks, but it wasn't until he played that card against an L2 judge, in the quarterfinals, that it was noticed. (Ironically, when he showed me his deck before the event, I asked ‘are you sure those are still legal?’… since I wasn't judging, I didn't pursue it.)
Instead of “courtesy” checks, we should just ensure that all the Top players have been deck checked during the Swiss. I like this innovation from the Pro Tour (what we must call “The Finnish Method”, in honor of Johanna!), as it's yet another tool to achieve the ultimate goal.
d:^D