Won't this do about what you want ?
Edit: Seems like it would work but could not see any results. Perhaps I don't understand how it's suppose to work.
Edit 2: You have to select 'SNR Strong decodes' or 'SNR Weak Decodes' (I was using "all decodes") in the 'Panels'. The "threshold" you select picks the dividing point.
FTdx-5000, Timewave Navigator, WSJT-x 2.5.0, JTAlert 2.50.6, HRD Deluxe v126.96.36.1997
FTdx-3000, SignaLink USB