Predict Vector after AngularVelocity applies

I just know this should be straightforward, but I cant find what I need in the objects.

Given a rigidbody which is rotating on the spot. I can get it’s angular velocity and its current transform.forward easily enough, but I want a function that will let me rotate transform.forward by (angularvelocity x t) so I can predict what the objects forward vector will be assuming that the same angularvelocity continues to apply for the next t seconds.
and, importantly, I want to do it WITHOUT actually rotating the transform. So transform.rotate is out. I want to predict it, not change it.

(Ignore angular drag for the moment, I just want a simplest case.)

I think I’m just missing the right Vector3 function or something but I get confused because angularvelocity is a vector not a quaternion.

Any help is appreciated

This is untested but should work:

   var v3NewForward = Quaternion.Euler(rigidbody.velocity * t) * transform.forward;

‘t’ is the time in seconds.