So I'm thinking if there is a way to mod in a way for ships to not achieve max speed so easily. It doesn't matter if you set max speed at 200m/s or 1000m/s achieving that speed seems to be possible with almost any ship. What I would like is to make it much harder to keep accelerating forward in atmosphere. I think the vertical acceleration is in a really good spot right now, but the horizontal acceleration speed seems to just be overkill because it doesn't slow down. I'm not really sure what it is that keeps real planes from not accelerating infinitely in atmosphere. Heat? Planes getting ripped from too many G-forces? Something else, maybe. Anyway, I would like to mod in a limiting factor so you would have to make specialized craft for long travelling in speed.