In my area, the most common practice is to just add a 2x4 or such added to the bottom of the ridge board to fill up the space.

I have had discussions with many structural engineers about this. In their opinion, there may not be that big of a problem if the span is not that great, and the difference between the rafter/ridge is not either. Such as when the span is maybe 12' total and the difference is 3/4".

I'll look thru my photos and see if I can find a split rafter.
JF