Hmm, there are two ways I can interpret what you wrote.
So the way acceleration works right now is that you have a maximum speed you can’t exceed (wow, there’s a snarky discouraging insult in there somewhere. :) Pressing Up adds some amount of delta to your speed based on how far forward you’ve pushed the stick. But you can never exceed the maximum, you just approach it more quickly.
Are you suggesting that turning work the exact same way, where you ramp up or down from the maximum turn speed based on how far left/right the stick is? Or that your maximum turn speed is determined by how far left/right the stick is, and you ramp up and down to that at some fixed rate?
Would like to hear other folks chime in here. It breaks from the traditional “center and shoot” mechanic of most audio games, but maybe that’s past due anyway.