opamp regulator using supply rail

hi there,
in some power amp designs a opamp in the input stage dumps its output current in a resistive load using the supply rails to bring the signal to the next stage (e.g. alexander cfb amp, pax, SAC igel). as far as i know this topology was never applied to a power supply or voltage regulator, so i ask wether this would make sense:
regulator.png


i did not built the circuit, in simulation it seems to work, but i have no idea wether its stable or worth to try...

cheers
thomas bachert