For the electronics enthusiasts, I took some measurements so you don't have to. Here are the facts:

12v rail voltage: The 12v regulator will read 12v at the input, and close to 10.6v at the output. This is OK for the drive. If there is any drop in motor speed, you may correct it with the trim pot adjustment. Just remember you may as well connect the 12v line to the output of the regulator.

5v rail voltage: The 5v regulator will read close to 11.2v at the input and 5.0v at the output. This is OK and the stock heat dissipator will take care of the heat.

Temperature: After 20 minutes at 22°C ambient temp, the 12v regulator reads 37°C and the 5v regulator reads 47°C . This is all well within operating range.

Current: After switching on, the current drawn from the new power supply reads 630mA (which is normal since it feeds all the electronics circuitry). When the motors are in operation, the total current reads 1,170mA (~1.2 Amps).

Heat: Your unit will now produce less heat: Since you disabled the voltage doubler, the 12v reg has very little work to do now, and thus, less heat to dissipate. The 5v reg has to drop 0.3v more than before, almost negligible.

The current readings above, mean that any nominal 12v/2A or better yet 2.5A DC power supply will be powerful enough.

Equipment used for taking measurements: Fluke 87V multimeter, Rigol DS 1054Z scope, HTI thermal camera.