A big thumbs-up for Sun Honda's Service Manager, Mike. I had talked to him week before last about this issue and he said he had just finished reading "Wrench," Honda's internal service publication, and hadn't noticed anything about any issues with the NT. He told me that if I got more info to email it to him.
So I sent him what DaveFL shared with us last week and just got a call. Mike has ordered the plug caps because, he said, "I don't want you having any trouble. I'll call you when they come in."
Good job, Mike!