Im curious why

Hello again Twinzz

If you're going back to thinking about linear regulators, then the answer is no. All that would do is change where the power is being wasted. e.g. let's say your 1.2V regulator is supplying 100mA. That current is being drawn through the 3.3V regulator and the 5V regulator, adding to their individual dissipation. You've had to drop the same number of volts to get down to 1.2V. There's no getting away from it, linear regulators waste power.

If you're thinking of switching regulators, I think a similar argument would apply. I'd try looking for a multi-voltage output device or use separate regulators from a single supply.

As a matter of interest, my prototype board is now up and running with linear regulators and they're barely warm. However, my board goes in to a current injection set which could draw 10A from a 230V supply so low power consumption is not an issue.

Best regards