It seems to me that a buck/boost converter would provide the optimal power available to the load. The current to the load will always be a function the target voltage (eg 13.2V) and the load impedance. Whether the PV is above or below the target voltage, the converter will always be trying to supply the needed current at the output by drawing the whatever current from the PV to attempt to maintain Pout = Pin (limited of course by the maximum current available from the PV.)
So if you are strictly/only interested in maintaining the maximum power point, would not a buck/boost converter work for that?
So if you are strictly/only interested in maintaining the maximum power point, would not a buck/boost converter work for that?