I do believe I've " solved" my issue by " inventing" a way to "adjust" the output voltage to track an input voltage and a way to sense the bidirectional current to a load, then merging the two. The merged result, as I've scaled it. sources/sinks cell current to the isolated output as well as the un-isolated output (which is a wire between all modules where I had previously tied the outputs together) Both the isolated and un_isolated outputs are at "cell voltage" , independent of the internal reference, but the un-isolated has a larger current capability due to the "step-down transformer. Further within an input range between 10 volts and 14.4 volts it's outputs are at 1/4 of V in. while for higher input voltage the outputs are limited to 3.6 volts.. For inputs below 10/0 volts the circuit is " powered down" To do it I have added 2 low current NPN transistors and 7 resistors and a low current diode.. The diode was the last addition, it allows the input voltage to go above 14.4. As I reread my initial post, I was confused by my description of the circuit on the secondary side of the transformer. To end the confusion. the Power MOSFET has its gate/source driven by a independent winding. The "power" winding" is between source and battery with the other terminal of the battery connected to the drain. Battery polarity must not forward bias the body diode.
Regards Jerry.
