All Investigation Clues Chapter 2 (The Witcher)

I really like this quest line, but unfortunately I haven't been able to collect all the evidence.
As far as I understand in the game, for each suspect, you can either find 3 circumstantial evidence, or 1 irrefutable. Circumstantial evidence can be used to prove the innocence or the guilt of the suspects, depending on Gerald's responses to the suspects' acquittal of the evidence. (like “I believe you” or “I don’t believe you”) If the answer to all the evidence “I believe you” Gerald decides that the suspect is innocent and, accordingly, if he answers “I don’t believe you”, then he is guilty. All the suspects have irrefutable evidence of innocence, except Grave and Kalkstein, which is why they became the main suspects in the Anatomy of a Crime quest.
So here's what I managed to find in the game:

Investigation

Suspect Kalkstein:
Circumstantial evidence:
- Talk to Thaler about Berengar's things, and then Kalkstein
- Complete the quest "An Important Witness for the Prosecution"
-? With the help of the editor, Djinni watched what Gerald would say when presenting evidence to Kalkstein: “Tell me more about your magical abilities. Hazard often uses the power of magicians. He could use you too. " But how to get this evidence is not clear, perhaps this is a blooper of developers.

Suspect's Grave:
Circumstantial evidence:
- Talk to Brick about the Salamanders
- Talk to a random bandit near the tavern
- Complete the quest "An Important Witness for the Prosecution"

Suspect Vincent:
Circumstantial evidence:
- Kill Salandra's bandits in the sewers after hunting Kakatrix
- Talk to the guard at the gate about the Salamanders during the day
- Hire Raymond to investigate
Irrefutable Evidence:
Complete the Rat quest

Vivaldi's Suspect:
Circumstantial evidence:
- Talk to Yuz about the Professor or read the list of suspects given Raymond in stage 9 of the "Secrets of Vyzima" quest
- Talk to a random dwarf in the Quarter of Inhumans
- Get the quest "Worth its weight in gold" from Yaevinn in the swamps.
Irrefutable evidence:
Ask Zoltan about Vivaldi's bank

Suspect Leuvaarden:
Indirect evidence:
- Talk to a random mercenary guard on the Dam or read the list of suspects that Raymond gives in stage 9 of the quest "Secrets of Vizima"
- Read the letter from the corpse of the messenger on the wyvern island near the Druid Grove in the swamps
- The super-buggy and hard-to-find evidence is as follows: From the beginning of Chapter 2, DO NOT speak to Leuvaarden in ANY CASE (not verified, but it is better not to read the letter of the messenger from the island of wyverns, and also not to speak with the hired guards on the Dam), until then until Raymond is attacked in the "Secrets of Vizima" quest and he runs away leaving you with a list of suspects, which will be in the quest items. Then we go and talk to Zoltan. He will have the opportunity to ask who is the richest man in the Temple Quarter. But keep in mind, if you have not asked Zoltan about the Vivaldi bank before this moment, this opportunity will disappear. In addition, this evidence, although it appears in the Diary, cannot be used in dialogue with Leuvaarden. Maybe this is not evidence at all, but just another useless entry in the Diary, which does not affect anything. I looked in the editor,
Irrefutable evidence:
Reach the sixth stage in the "Wanted" quest

Suspect Thaler:
Circumstantial evidence:
- Talk to Thaler about Berengar's things
- Talk to Hughes about the witcher's sword for a dose of Fisstech or read the list of suspects that Raymond gives in stage 9 of the Secrets of Vyzyma quest
- Talk to the "mysterious man" at Thaler's house from 10 pm to midnight
Irrefutable evidence:
Complete the quest "My old friend"

Also, the innocence of all of the above is proved by the correct completion of the quest "Anatomy of a Crime" or the completion of the quest "The Gravedigger's Gratitude"

I could not find one indirect evidence for Kalkstein.
Please help me find the missing evidence!

However, perhaps due to the laziness of the developers, this evidence cannot be obtained. In this case, I propose to make a small mod that fixes this glitch.
For example, after the attack of the Salamanders on Raymond, he gives us a list of suspects, upon reading which we get entries in the Diary for new circumstantial evidence on Thaler, Vivaldi and Leuvaarden, if we did not get them in another way.
I propose to add the missing circumstantial evidence on Kalkstein and Leuvaarden to this list.
Unfortunately, I don't have the necessary knowledge to create such a mod. Maybe there is a kind soul who will help me make this wonderful game even better.