My company's F/O limits are Min ceiling 300', RVR 750M, X-wind 15 knts (A/C max 30) unless flying with a training captain. Previous company x-wind limit was 25 knts (A/C max 36).
The one before that (military) had no F/O limits. The F/Os were assumed to be trained to the same standard as the Captains and were treated like adults. When I was a captain on this aircraft, I made a point of letting the F/Os do approaches in these conditions - how else are they supposed to learn!