re 2 seconds delay:
25.149 (at the amendment to hand) makes no reference to time delays in discussing the VMC determination. AC25-7A also appears not to require any pilot delays for this. As far as I'm aware, our testing doesn't include a deliberate pilot delay time. A 2 second delay on Vmc would be ... interesting. Is that an old BCAR requirement, too?
re nosewheel steering. AC25-7A requires it to be OFF unless a pre amdt 25-42 aircraft, on a wet runway. We turn ours off, consequently. This provides a degree of wet runway simulation, although it's not perfect of course.
[i]edit: and another example of Vmca/Vmcg variation. With modern type rudder systems, incorporating travel limiters or FBW type controls, it would be easy to conceive of an aircraft with very different rudder authority limits in-air and on-ground. As a result one might have very different Vmca and Vmcg values, which would allow them to switch magnitudes.