NCs that don't age well?
All of them
Sorry I am just a CC Snob

I did smoke NC's for a many years and went through all the high end lines Padron, Opus x, Diamond Crown, Hemingway, Don Carlos ext. I worked PT at a cigar shop and lounge for 10 years. So I have smoked Ashton to Zino and most all in-between (I smoked 4 to 5 cigars a day)
I can't tell you why CC's age better then NCs. But I can tell you I have smoked 1000s of Vintage CCs 20 year old + and 95% have been outstanding.
But I can tell you that NC's after 10 years go flat. (for my palate)
If I had to pick some NC's that may hold up and even get better they would probably be on the stronger side.
Camacho
Don Pepin
Joya De Nicaragua
Drew Estate Liga Privada
Ashton VSG
Tatuaje