Assuming the same fork rake and same HTA, fork offset and trail. How much do you think a change of 1.5cm will make. I am on the fence between a 58 and 61 CX bike.
If the wheel is moved to where the CofG is behind it more, a bit lighter feel, steering is possible,
but it may take a greater distance than 15mm . and you may shift your body mass forward with it and then it will be un noticeable
Plan Cyclo cross racing or just getting a Cross bike for the wider tire capacity?