After touching Iona’s Bloom and running about 30 seconds through the ‘scripted’ path, you can jump onto some rocks and glitch through the wall.
Unlisted video here: https://www.youtube.com/watch?v=s8ixENQcyt8
Although not a part of the recording, I experienced an additional bug with this interaction, where if you die while out of bounds to the right (notice how I go to the left once through and jump, landing near the entrance to the Potion Seller’s hideout), you will respawn with the Iona’s Bloom affect still applied, basically soft locking your character. This is because the pathways leading to and from the potion seller have a magic barrier. The effect remained after death.
The only fix is to exit to the main menu, and select the option that lets you enter the realm at the last bonfire.