How to send from one serial port to another?

Like this lib a lot since it cleans up my messy code.  But because of the requirement to use `sender->GetSerial()->println(...)` I can't figure out how to read some from one port and send to the other.  Does every print have to be triggered by a handler?  Is there a way to just address a print to a specific serial port without it being the result of an incoming command?