CJ4: 1/2 HW + full gust. Max 20kts over Vref. The 510 was the same as I recall.
So with my earlier example +4 and +10 for a Vref of 118kts instead of 104?
That seems a little excessive.
Vref 104 in a no-wind is a GS of 104 and you're landing distance is taken from the table, let's say 2850'.
Now you have a 10 kts HW component with no correction on Vref your GS is 94 and your landing distance will be less then 2850', increasing your safety margin.
If you apply a HW correction and therefore increase Vref you are increasing your GS again and getting closer again to your original number of 2850'.
I don't understand the purpose of this practice.