https://stackoverflow.com/questions/66286367/why-is-my-function-faster-than-pythons-print-function-in-idle had some tests of printing speed that showed that print in IDLE can be much slower than in REPL.  I did further tests that showed than combining chunks and lines into a single string can erase most of the difference.

For easier review, the first patch just rearranges current paragraphs to bring together those dealing with 2 processes and sys.stdxxx.  Some are also re-wrapped. The second patch will contain just the new paragraph.