@ion_ag
Hi, this is already available but only on the website windy.com, not in the app.
Tap your right button on mouse and select Distance & planning. This feature is called Route planner.

https://community.windy.com/topic/9013/windy-launches-route-planner?_=1631006164227

https://community.windy.com/topic/9596/how-to-use-a-route-planner

Now you can adjust the speed of movement along the route and set the wind reference to North up.
If you just need a vertical cut, untick the speed.