I don't use KP, but I have a pdf for my floor safe in my password manager. I only open it a few times per year and I need more than just the combination, I need instructions on whether the first number is cw or ccw. While I could no doubt look it up on the internet every time, I was fearful that the user's manual might some day disappear from the internet. Some things that aren't obviously passwords still belong in a password manager.
Were that me (I used KP), it would be in a different kdbx file. This is one of the benefits of KP, I have about 8 different vaults for various things. I don't like putting my eggs in one basket.
In my mental model, the PDF is not a secret and can be stored anywhere -- encrypted, if desired, but it sounds like a public document.
The safe combination is a secret, and obviously belongs in secret storage.
In this specific example, if I had trouble remembering whether the first number of the combination was reached via cw or ccw rotations, I'd include that in the secret, e.g. "cw34-12-22-45".
(Some safe combinations require multiple rotations. I unintentionally became the owner of one that is something like "cw3x34-ccw2x12-cw5x22-ccw2x45". I still can't open it actually, but that pattern is what the Internet tells me. :)