There is no requirement to be inputting winds for every waypoint!
Agreed! Our technique, if manual input is required, is to input the first waypoint after TOC, after a [planned] change in altitude, and when the forecast wind changes by 10 knots or 30 degrees.
If we are pressed for time before T/O, we input the average trip wind in the first waypoint after TOC. Then we input the forecast winds when we're settled in cruise.