I've adjusted the tappets on the two Jazz cars we have owned. By checking all of the gaps first, not all valves may actually need adjusting, which really is an easy job to do.
Those who say there is no tappet noise, ie, engine is very quiet when running, don't under stand, that, as a valve wears into the valve seats in the cylinder head, it actually closes the gap, not increases it. So checking / adjustment is all important. I really think a manufacture of Honda's standing, wouldn't put it in the service plan, if it wasn't necessory.
rog....