You can also make functional elevated ledges in an RPG Overworld. Just copy an empty level tile that's already set up, change it's level number to an unused one (since level tile settings are per level number), and disable the directions that you shouldn't logically go in (off/through ledges, etc, except if there's no level tile in that direction). For my overworld, I use 9 different level numbers for level tiles with different enabled directions (some star road levels are overridden):
0 = all directions enabled
132 = up, down, right
133 = up, right
134 = up, left, right
135 = up, left
136 = up, down, left
139 = down, left
13A = down, left, right
13B = down, right
Here's a
base RPG Overworld hack I just made with some ledges set up with the right level tiles, and with the RPG Overworld patch applied. Also, Palette 6, color 7 of the Overworld palette is changed to rgb 64, 208, 32 to make the ledges look right.
It's also possible to place level tiles in Layer 1 events, so you can have unlockable paths this way. You can't edit their settings directly when placed in a Layer 1 event, but they will have the same directions enabled as the level number of the tile you copied/pasted.