That I can try.
Time to bring this back to OP before Irish or Uncle Ben shows up. I'm in the camp that you should close it if you're not going to use it, life is too short to worry about and babysit a bunch of useless SD cards, and even though I have no evidence that how cards are closed would affect your profile, common sense tells me "closed by consumer" is cleaner and raises less questions than "closed by granter" during manual review.
Ill second Saeren's point on some lender may frown on closing a card before 1st year is up. Even though i wont app again for Chase cards, i believe me closing my Amazon Visa before year one has put me on a blacklist. Just my gut feeling.
If you are gonna close cards that arent in it for the long haul, id prefer to do it early while the age is young than wait til account has a couple years. Just an sverage penny.
While anything is possible, I really don't think closing an account before a year is going to put anyone on a blacklist. There's nothing negative about it. You just decided you didn't want the account.
Now, if you did it repeatedly, I could see your point. But one or a couple times closing a young account isn't going to make a lender blacklist someone.