^ what my spellbook looks like after clearing debir and most of scarlet....i also dug out a battle cry scroll which doesn't exist in my game according to scanner report...
after extensive saving/loading on debir and scarlet, i think the
chance of yielding a wanderer scroll/rune/crystal/spell scroll/gold is the same for all the continents, it's just that you get more gold and better scrolls as the difficulty of the continents increases. for wanderer scroll/runes/crystals the amount (which is 1 for wanderer scroll/runes, a small number around 3 for crystals) stays the same. and i don't think the system ranks the wanderer scrolls either. this is just what i got so far, more testing is needed to yield more precise conclusions.
this means that if you are gonna do this kind of saving/loading for maximum chest profit, you gotta pick the dragon pet with chest digging skill and start from training!