Still haven't made it past desert in this build. Part of that is bad luck, but I find the desert basically impossible with reflect seed. Maybe if the aimed projectiles moved a touch slower? Or if they took a little longer to reload? Or both?
I find I'm often on a screen with three aiming projectile enemies, and because you tend to just barely dodge their projectiles, the projectiles tend to take out any thorns you might have before you reach the enemy.
Having projectiles not hit thorns would also make them quite a bit less punishing.