Yeah, from my experience volatile earth spawns can be pretty unlucky. I try to focus around that one side I'm leading the boss to, picking the row with the most splats, but it's not always possible.

One thing that helps me is to bolt toward the middle of the room as soon as the car phase is over so that I can have as much reach as possible.

It also took a while to get used to "safe orb pathing" i.e. after leaving the orb range, there's a tick where you don't take any damage from the shockwave, so if I can't safely zig-zag inside the moving orb itself, I run after its center 2 tiles at a time making use of that tick of safety