I can understand why that is not allowed. Most ships would be spinning on a dime. I think djarnier ran into that issue. I don't have a problem with keeping the ships limited to thier rudders for maneuvering. There's got to be some limitations to keep the game practical and challenging. How would you regulate the amt of speed allowed for each prop to turn and not have it illegal? How much is too much? It would be difficult to regulate this. I think for this game those systems are best left to the non battling models which are built for scale effect. Kiss principal is a must for this hobby.
I found in the past, when turning systems were allowed, that turning off the inside motor on a turn was the most effective while moving but running in reverse worked better from a dead start. One of my early Warspites could turn around in the hot tub!
Interesting how changing speed on the inboard prop would improve turning. I would have thought it'd hurt your performance, since the inboard prop is the one that contributes most of the thrust for turning. On most of the boats I've seen, the rudder aims most of the inboard prop's thrust sideways to turn the boat, but the outside prop is only 50%, 25%, or even 0% redirected. By slowing down the prop that's providing most of your turning force, I thought you would actually hurt your performance. I guess it depends on the specific ship and its specific prop/rudder arrangement. BTW, tank-steering is not banned in my club. The rule is that you cannot exceed the RPMs used to set your legal forward speed. So if both your motors turned 10,000 RPMs to move your ship at legal speed, then you get 10,000 RPMs in reverse, tank-steering, etc. Nobody really bothers with it though, due to the complexity and the lack of benefit for the effort required.
I find a ship like Nagato turns ver very tight without the independent prop control. Still be interesting to see one set up.
The Dimension engineering ESC can be set up using the dipswitches, to use a 2nd input, so that you can hook it up to the rudder control. That way with the one ESC, you have full mixing in the forward direction, the inner prop slows or will even reverse. If you do not apply any forward, but just rudder throw, the props run at full speed in oppisite directions, then give it little throttle, it makes the boat turn very nice, and is a very simple setup. But this is not allowed in the MWC. I have tried it with my Roma, and she rotated in circles. Sounds like you should try one in your new VU.