So, I broke out some old physics formula books and had some sort of a revelation. I added updateTime = (float)gameTime.ElapsedGameTime.TotalSeconds; into the main update function of the character and changed the following code and now it seems to work (?):
private float accelDistance = 20f;
private float decelDistance = 60f;
public float velocityMaximum = 180f;
private float updateTime;
public float Acceleration { protected get { return accelDistance * updateTime; } set { accelDistance = value; } }
public float Deceleration { protected get { return decelDistance * updateTime; } set { decelDistance = value; } }
public float VelocityMaximum { protected get { return velocityMaximum * updateTime; } set { velocityMaximum = value; } }
```