Yes, good shot!! Good and simple idea: use 2400bps for the data transfer.
It will take a little bit longer for the upload, but I can still use the board with the 2MHz crystal for developing and tests...
For the debug, I only have to set the baud rate of the serial terminal to 2400bps (assuming that I am using Serial.begin(19200) at the code).
I will try these ideas tomorrow.
Thanks