DJ, try a small backpack with a block of foam or stiff plastic inserted, stuff the pack so the block is held secure against your back. Attach the extension pole to the foam and position the pole behind/above you. Sure it will wobble when you paddle, but edited that out like you do now. Effectively, you become the tripod and gyro so the horizon should remain relatively horizontal.
I have a picture of the rig somewhere I'll post it when I find it.
Similar to this but with pole extended further.