Honda were very very late to this party,
Toyota did that on their ancient 3tgte engine found in corona gt, nissan did that on their old stanzas and mercedes did that on the old m112 and m113 engines. It was to induce a fuller burn to make older tech engines comply to lower emmission standards.
Newer engines dont need that help now.
Some old bike people can tell you of twin plugging bmw flat engines from ancient times to eek better and reliable starting.