I don't use the rivers mod, but "The Edge" spawns you in a valley with mushrooms, fruit bushes, reeds in nearby ponds, a few nearby trees (one of them seems guaranteed to produce resin), a snowcapped mesa to the north, nearby caves are sheer vertical drops but don't seem to go too deep? ...And you spawn next to two huge piles of Bauxite.
I haven't played with this seed long, too busy futzing with world gen settings trying to find a mix where it's not either endless landmass or an ocean world of small islands. Just noted how solid a spawn "The Edge" is for a seed. If you're unlucky, bears might spawn nearby, but that's as bad as it gets.