Thanks for answering I actual had a go ( several go ) at CTS/RTS with no luck.
My system would set the two senders starting in transparent mode ( successfully sending every received data )
then the controller, in api mode, would put cts in the first sender, and receive the second.
Then cts the second, and undo cts the first and so on.
The problem I encountered was that CTS behavior was quite unpredictable, first the values 0, 1 wouldnt stop the sending, so i had to set it to 03 or 04, weird but okay if it works thats cool, the thing is, it did work only once in a while, whith the cts pin set to 03 or 04 ( and i checked every time to be sure ) i would sometimes still behave as if nothing, or sometimes stop sending but dont buffer anything ensuing lots of loss.
I'm all with you when saying there must be room for some loss, but at this point there is way more loss than anything