TX pin incorrect?

[EdKok]

Thanks for the great project. But could it be that there is a mistake in the documentation for which pin to use? According to the README.md:
"Connect the Victron product VE.Direct TX pin (via the logic level converter, if necessary) to ESP32 GPIO pin 17."
But this didn't work for me until I used pin-16.

[EdKok]

And on this subject, why is there also a TXPin?
Serial1.begin(19200, SERIAL_8N1, kRXPin, kTXPin, false);

And the comment in the code // initialize Serial1 on the opto_in pin suggest to use an opto-coupler, but then the last element of that line (boolean) should be true.