If you have access to the top part of Bumper Cave, you can use Hookshot to get through the bumper, which will lead to Dark East Death Mountain where you can drop down the ledge to get to Swamp Palace
#Stuck in an unsolvable seed
pearl junco
sonic jacinth
Wow, great, thanks for the quick answer...mind blowing how we couldn't know this after a lot of runs... 🙂