LEAT can be asked for records by a donor, by a member of the public, by somebody asking what LEAT holds about them, or by a court.
Because a black box drawn over text usually leaves the text in the file. LEAT produces a genuinely redacted copy and then checks the result before anything is released. A copy that has not passed that check cannot go out, and one failure stops the whole package.
A link that expires, is tied to you, can be used a limited number of times and can be withdrawn. There is no permanent link, and forwarding the link does not give somebody else access.
Whether a document exists that you are not entitled to see. A refusal and "there is nothing" look the same on purpose, because the difference between them is itself information.
A refusal is a decision and it can be appealed. The appeal is recorded against the original so both are on the file.