Thank you to the WSJT-X team for incorporating a "no shaping" option into v2.3.0. It will be greatly appreciated by many FST4 and FST4W users. Reading the release notes, the comment is:
FST4/W: Disable envelope shaping at start and end of transmission
when environment variable FST4_NOSHAPING=1. Works for fst4sim too.
Not being a Windows power user, I wonder if someone might tell me the easiest way of setting the required environment variable? My WSJT-X 64-bit installation is pretty standard, with default paths etc. The v2.3.0 manual gave some clues about the use of environment variables for other applications but I must admit that a quick search hasn't turned up the variable list I was expecting.