I agree that highly figured wood can wind up competing with carving for the observer's attention. While the carving isn't totally lost, it tends to get overpowered by the wood itself. The actual area of the carving can get overly "busy looking", and actually drive the observer's attention AWAY from the area rather than draw it TO it. Sort of like how smelling salts overpower your nose and force you to turn away from them.
In cases like that you can do some things to lessen the power of the wood grain. For instance, you can apply just a little more stain to the carved area and darken it slightly more than the rest of the stock. It's going to naturally want to take in more stain anyway due to the exposure of so much more end grain (incised carving even more than raised). Then, with raised carving take some steel wool and knock back the stain. That will lighten the tops more but leave the stain in the recessed areas. The tops in your carving will be even lighter colored than the surrounding base plain of the stock, and become something of a natural "eye magnet". Overall, that will give more contrast and call more attention to the carving, while deemphasizing the grain within the carving itself at the same time. You might even do it a little bit with the areas around the carving to sort of "frame" it.
Just experiment a little bit to see how best to deal with it. Take some figured scrap and carve a few volutes and play around with it.
Metal inlets / inserts need no such treatment because the nature of them is entirely devoid of competing figure. The DO however cry out to be engraved.