Accidentally Accurate: Whether Rosa meant it or not, we can't be certain, but his depiction of the Whiskervilles dashing harmlessly across quicksand in their panic in "The Last of Clan McDuck" is scientifically accurate, as quicksand is a non-Newtonian fluid, meaning that one can run across it without sinking into it.
Creator Backlash: Don Rosa claims he didn't like thinking of "Of Ducks, Dimes, and Destinies" as a Stable Time Loop, with Magica unintentionally behind the origin of Scrooge's fortune. He prefers to believe that Magica undoing the effects of her Time Travel undid her time travel trip entirely.
Doing It for the Art: Or more specifically doing it for the story. Don Rosa has stated that he's actually not a big fan of drawing long pieces - it's telling a story that drives his motivation.
Shrug of God: In regards to The Prisoner Of White Agony Creek.
"I still never show exactly what happened that long night in the cabin on White Agony Creek... that's for each of us duck fans to imagine in our own minds. I have my own idea, but after all, this is a Disney comic!"
~Keno Don Rosa, The Making of Hearts of the Yukon
Working Title: Several chapters underwent title changes in the development process:
Chapter VI ("The Terror of the Transvaal") was originally "The Prey of the Transvaal Viper".note Changed at the request of Rosa's editor, who thought the original title was too negative. Note that the villain is referred to as "a viper" several times in the story.
Chapter VIII ("The King of the Klondike"), started as "The Phoenix of White Agony Creek", and then changed to "The Argonaut of White Agony Creek".note The title it goes by in European markets before settling on the current title.
Finally, chapter IX ("The Billionaire of Dismal Downs") was originally "The Pariah of Dismal Downs".
Rosa's drafts show several changes such as — a cut sequence telling the whole history of the Clan McDuck, a Cat Fight between Goldie and a middle-aged Grandma Duck, and Scrooge's sisters never accompanying him when he attacks the voodoo village in the Congo.
When Scrooge and Goldie have their fight in the cabin that suddenly... stops, Don Rosa wanted to draw the snow on the rooftop melting, but figured it would be the line with the censors he couldn't cross. (It does occur a page later though.)
"The Dream of a Lifetime" would originally have been a time-travel story, but Don Rosa realized he needed Scrooge to know who Donald and the new generation of Beagle Boys were when they visited his past, hence it turned into a dream-visit story instead.