the above mentioned option does not seem to work. Several times the weather update unluckily started right at the runway threshold or even in the flare phase, providing me with some extra challenge during landing the Dash 8 Q400 since the frame rate of my sim drops significantly during weather update. I should mention that I am running FSRealWX v.3.x as a client on a network PC. In the previous 2.x versions of FSRealWx this option seemed to work flawlessly. I never experienced a weather update during the critical approach and landing phase and the status line at the bottom of the program window informed me accordingly.
I could disconnect FSRealWx manually but due to the high work load during approach and landing I almost always forget to do that.