V, a steel fork can be harsh. Just like frames - it depends on the tubing, the design, the geometry, the rake, etc. The steel fork on my Mercian is probably much like your Riv. Fabulous, comfy ride. The steel fork on my Kelly cross bike is very rigid as it needs to be for cross racing. The Alpha Q carbon road fork on my Kelly road bike is somewhere in the middle.
Matter of fact, Bill replaced his Kelly cross fork with an Alpha Q carbon to get more compliance. The steel cross fork was very harsh on the road.
It just depends. That's one reason why one really can't state categorically that one material is stiffer than another. Knowledgeable builders can do incredible things with each material.
Frends know gud humors when dey is hear it. ~ Da Crockydiles of ZZE.