David Weaver
If you can plane a board with a modestly thick shaving (using the cap iron set on a smoother), and have nothing other than a small amount of surface smoothness issue (in ribboning or quartered wood), you can often back the shaving off to something thin, and make several passes and remove any issues.

It's uncommon for wood to not tolerate that, especially if you'll be sanding with 220 grit or something after the planing. In my experience, there isn't much as far as defects in most wood that can't be quickly removed with 220 grit to extreme uniformity.

Much of this absolute lack of uniformity (the kind of spots that you'll notice tiny bits of dust accumulating on first pass with sandpaper) is what gives wood characteristic depth when planed that sanded wood lacks.

At any rate, back off of the shaving to half or a third and see if things improve. In my experience, the rare wood that doesn't respond to such a thing, even when you change the direction of planing, is something that just won't plane well.

The benefit of the cap iron is that even on the woods that require a final thin set of shavings, you get there much faster because such woods don't tolerate planing anything thick without a cap iron.