Yes but I am really begginer here . I made a plugin for surf boost for my server and I used that stock and velocity but when I pressed space it threw me sometimes out of surface so let more experienced scripter to answer here how to set velocity correctly so that player had the same moving direction afterwards.
I've made lot of plugins , maybe I'll post them.One of them is speed boost on surf by pressing space, I think the same plugin you are looking for.