These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Trylle Trilogy
Fridge Logic: If the Vittra promised not to attack Forening until Wendy becomes Queen, why didn't Elora swallow her pride and marry Garrett Strom, giving Willa a shot at the crown?
They Wasted a Perfectly Good Character: In the bonus material in the printed books, it's revealed that there are trolls in other villages that have gills and ones that can change their appearance to blend in with their surroundings, as well as traditional ugly, temperamental trolls. They are never brought up or explored in the actual story.