Sorry for such a long comment in advance.
I have been thinking quite a bit about having inputs for fuel and altitude, which could give indication of the current state of your creation. For example: having “input : Fuel” would provide part movement based on % of the fuel remaining from total fuel, so when the craft has 100% fuel, the part gives maximum movement, when zero fuel remains the part will zero out or travel to the minimum point. As for altitude, “input : Altitude=(value)” would give movement as a percentage of desired altitude value, so if the input was “Altitude=12000”, and the craft was at 6000ft, it would indicate 50% movement of the part.
Having this kind of input design would also greatly benefit the “V” input for simple and low part count gauges, and It certainly wouldn’t be a huge addition to the game, though potentially useful to have alongside environment additions. More ship convoys and maybe an island with more trees, almost swamp or jungle-like or an iced-over island airport would make great additions.