[robski]

I don't have any call to use Bridge and I am sure that your method does work to edit a jpg in ACR and of course the controls will work in the same way.

What I do question is your logic that you have the original RAW data in the jpeg.

Camera RAW is normally 12 or 14 bit data dependant on model of camera. Jpeg is only 8 bit data RGB.

The 8bit data is derived from the 12/14 bit data after gamma curves have been applied based on brightness, contrast, saturation, colour balance and exposure settings.

In some cases the only difference between 100 ISO and 200 ISO is the gamma curve applied.

Readjusting these based on jpeg 8bit data is not better than adjusting in Photoshop other than the controls maybe more intuitive.

It will be interesting to see a correction for 2 stop under or over exposure using your method compared to processing the original RAW file.
Or even temperature correct for a camera set up for tungsten lighting but shot in daylight.