The want being to only feed the USART when it's ready, no buffer but the port, and return fail if the port flags indicate that it's in use. Even a version of Print.available() would be an improvement.
When I read the ATMEL docs I see the registers and which bits and then I see that Serial and Print use and may change modes that me not knowing JAVA stopped at the Serial source. I'm too old for that mountain and what I do too.
I just want to be able to print the way I read which is without blocking code execution. If you know what modes the USART runs by, any changes that make a difference to the empty/ready bits then please even the info is welcome.
PS -- you see, I have text in PROGMEM that would not need buffering and blocking to print.