MU messages not always fully delivered to 00_SignalDuino.pm

[auron-muc]

I had massive problems trying to get some FLAMINGO FA22RF to work on a USB-Maple-Signalduno.
I used the PCB by Ranseyer, and other protocols were going just fine.
When monitoring from vscode after uploading via platformio, all messages looked valid, too.

I finally added a lot of debugging output 00_Signalduino.pm (and even DevIO.pm) an noticed that quite a lot of times during the massive flood of messages a new MU; was sent without the previous message being ended with a \003\n

I think it all is due to the TX message buffer sometimes being overwritten, if the polling USB client is too slow. The buffer is only 64 Bytes by default.
[ https://github.com/rogerclarkmelbourne/Arduino_STM32/blob/master/STM32F1/system/libmaple/include/libmaple/usart.h ] -> USART_TX_BUF_SIZE

I tried increasing the buffer to 255 by adding "-D USART_TX_BUF_SIZE=255" to the build options in platformio.ini, but that did not help. Neither did adding the define to compile_config.h
My current solution is to add a flush() to every print() by modifying the macro in output.h

I will attach a diff

[auron-muc]

output.h.diff.txt