In Eladi Cavern B2 (I think it was), you can obtain an Escape Rope from the item ball beyond the Rock Smash rock. (It's a Key Item version, for reader context.)
However, by that point, you can just purchase the Escape Rope from the Poke Mart, as it becomes available to do so upon obtaining the Fist Badge. This makes the Escape Rope behind the Rock Smash rock in Eladi Cavern a wasted item; it's particularly so because you only need 1 (and can only have 1), as well as due to needing to backtrack/go out of the way to obtain it.
EDIT: Another bug/oversight, this one more pressing. At the Route 2 entrance to Eladi Cavern, it's possible to jump southward down the ledge and be trapped between the mountain to the left, the tree to the south, and the Eladi Cavern sign to the right.
I saved beforehand before jumping to take the screenshot to show exactly where it is a player can get stuck. But if a player were to save their game after jumping down, they wouldn't be able to leave under normal means, so I think it'd be a good idea to swap the side of the ledge where the sign is.
EDIT 2: The passenger ship to ferries between Magnia City and Tartha Island cost 25 Pokedollars. Just out of curiosity, are there any failsafes in place in case of a soft lock if the player runs out of money, partcularly while on Tartha Island?