The "Local destination recipient limit" option limits the number of recipients per local message delivery. The default limit is taken from the "Default destination recipient limit" option.
However, the queue manager by design limits the number of recipients per local delivery request to exactly 1, so this parameter has no effect.
The "Prepend delivered header" option control when Postfix should prepend a Delivered-To: message header.
By default, Postfix prepends a Delivered-To: header when forwarding mail and when delivering to file (mailbox) and command. Turning off the Delivered-To: header when forwarding mail is not recommended.