I mean you can ask for that but so far my thoughts on this one go mostly in circles.
Question: When was the letter written?
Assumption: The letter was not fully written before the events.
How solid is this?
It is backed up by:
Assumption: The culprit could not have guessed every event described in the letter.
How solid is this?
Fact: Krauss chose the number in Battler’s game at complete random. It was impossible to guess for anyone but Krauss.
Question: Could it have been written beforehand regardless?
Yes, in fact. Going by pure logic, nothing stops anyone from writing down whatever they want.
Not their fault if it’s then interpreted as a magical prediction. Heck, in a game titled after the witch of miracles, a completely random troll letter turning out to match up with events against all odds would not even be something to exclude.
The thing that stands against it is:
Fact: The contents of the letter would have been the same regardless of Krauss’ guess.
Does this rule out guessing and turning out to be right?
Most likely, as any pre-written letter could have very-well turned out to be wrong.
There’s no way around that, really, unless we question the nature of the narrative itself and assume there was something about it that made the letter ‘destined’ to be correct.
All in all, so far it seems reasonable to conclude:
(A part of) the letter was written after the culprit witnessed the events described.
Question: When was the letter placed on the table?
Fact: The letter can only be switched by hand.
One could question the definiton of ‘switch’, but aside from that it seems solid.
Fact: Krauss would have seen anyone reaching for the letter within his area of awareness.
Assumption: At no point was the letter outside that area of awareness.
This one might still be possible to get around.
It would require one of these things:
1.) moving the letter
2.) moving the table
3.) moving Krauss
All of these seem hard to pull off subtly, especially with the table being completely ordinary.
Hm, ultimately this one is still inconclusive, although I have a hard time coming up with anything that would fit.
Let us temporarily assume it cannot be done, just to test if there are any other areas of attack.
In that case, the conclusion would be that the letter could not be switched.
And if it wasn’t switched, then it was placed when Genji placed it. Which leaves us with the paradox of writing a letter after it’s been placed.
Question: If it wasn’t switched, can one write the letter after it’s placed on the table?
Fact: The letter was handwritten with a normal pen
Hard to get around that one except with rather exotic penmanship techniques.
The letter was blocked by a statue from the top and a table from the bottom.
It’s fair to assume no pen would fit between this, unless the statue was hollow, but handwritten does imply your hand needs to be there to do it so we’d be back at the Krauss problem.
My conclusion here, given the previous conclusions, would be that from when Genji placed it until after Krauss read it there was no way to write on that letter.
Alas, writing it after then is meaningless.
Unless you time travel.
Other open questions:
What was the thing Krauss stepped on?
It was at the exit, not the kitchen. Meaning it’s unlikely to just be the explanation for Shannon’s accident.
It seems likely it’s connected to the letter trick, but what would help there?
How could the culprit have been prepared for the letter?
Depends on whether the trick is something you could just come up with on the spot.
The letter kind of came out of nowhere, who would have even known it’d be a thing aside from Kinzo (and maybe Genji)? And assuming the ring was stolen for that purpose there weren’t exactly many chances after dinner began.
And those are my thoughts for now.