Broken riser variants

Just wondering how to reduce the riser height, and I've heard about the broken riser which rises off the vertical.
So, can the flame path go vertically down, across and then up again without being a gassifying stove?
( gassifying wood stoves do this - the rams horn vortex forms in a combustion chamber below the primary chamber )

I'd imagine that you have to heat the vertical upwards path of the riser first before invoking a bypass which switches the path to down and then up.