It should be possible to add an attachment to the bank statement record.
At least in Finland auditors want that bank statement includes also account statement pdf (customers get it from bank).

So basically when you have and bank acc. reconciliation page open, you could attach a document.
When you post statement, the attachment come to posted statement.
It’s would be nice to be possible to add an attachment to posted statements afterwards.

(sometimes user forgot to attach file when doing bank reconciliation)