I assume we're talking about a cruise climb here...If you only need one or two hundred feet, just pitch up a little.
I guess, technically, you can climb as the expert suggests, but why? Flyboye can confirm or deny this, but I would bet that that's the jet answer. In a recip, add power, pitch to your cruise climb, and trim, because you're going to need full power to climb anyway. Theoretically, if you do it the expert's way, you shouldn't need to trim in the climb, and so won't have to re-trim when you go back to straight and level.
Does that help?