I am designing a 30 V 5 A lab bench power supply having SMPS as a pre-regulator for the linear stage which will keep the SMPS output always 4 V higher than the main output voltage. This means SMPS output will be varying from 4 V to 34 V. For SMPS, I have used forward topology and therefore it requires a minimum load to operate properly. After some trial and error in the simulation, I found out that it requires a 1.2 W minimum load at its output and therefore I want to have some margin and want to place a 2 W load at the output. But since the output voltage will be varying from 4 V to 30 V I can not just put a resistor at the output because if it is dissipating 2 W at 4 V then it will be dissipating 144.5 W at 34 V which is obviously not practical.
Is there any simple way that requires only a few components to overcome this problem?
EDIT: Extra details if required:
I am using UC3844 as the controller IC. Link to datasheet.
I have tried using opamp to maintain a constant voltage across a resistor and hence the power dissipated by it but the rest of the voltage is dropped across a BJT which is carrying the same current as of the resistor and therefore in total around 17 W (BJT and resistor combined) is dissipated at 34 V which is still pretty high.
This is my SMPS schematic: