@karlosgm Windy strives to be as accurate as possible. There are several different weather models available on Windy. The ECMWF is probably the most accurate. ICON EU is a new model introduced here a couple of months ago and can forecast most of Iceland. It is also very accurate. The GFS model is another good model but doesn't work too well in my part of the world. You might have a better experience with it in Iceland. Everybody has a different experience when using windy. So give different models a try and get used to the site to get the best results.
And wind gusts are already a feature on windy. Try clicking on the more layers button on the right layer menu, there should be a selection of many different layers where wind gusts should be near the top.