Bridge 188.8.131.522, Camera Raw 10.3, PS 19.1.4, Windows 7
You can open the file from Photoshop as Camera RAW, though. Choose File>Open... and click on Options in the dialog. You can then select your Photoshop file and choose Camera RAW from the Format menu.
This will open the file in the Camera RAW editor, and you can adjust the file's exposure and other settings like any other RAW file. The difference is that other applications won't respect the develop settings until you develop the PSD into something else. Even if you open the PSD in Photoshop as a Photoshop file (and not as RAW), you will not see your RAW edits. You will only see the RAW setting results in the RAW editor and when you either click Open Image or Save Image..., which will develop the PSD.
For the record embedded camera raw XMP develop settings data can be written into PSD files the same as with JPEG, TIFF, PNG, and DNG. When using Bridge menu Edit> Develop Settings> Clear Settings the embedded XMP develop settings are succesfully removed from all of the above mentioned file formats EXCEPT PSD. That is the issue I am reporting. I hope this makes it clearer. Thank you!
James thank you for the confirmation. I've done some more investigation on the root cause of this issue.
Lightroom can import and process raw, DNG, JPEG, PNG, PSD, and TIFF
files including layered files in both RGB and CMYK file format. In the
case of layered PSD files they must be saved with 'Maximize
Compatibility' checked. All of these file formats can have their LR
Develop settings saved to XMP metadata in the file with exception of raw
files, which use XMP sidecars.
It appears the Adobe Camera Raw Plugin and Bridge can only see, apply and clear XMP Develop settings in raw, DNG, JPEG, and TIFF file formats. PSD and PNG file format are not supported.
Lightroom and PS both use the same ACR plugin so why the difference? Depending on the response from Adobe this could remain as a "Bug" Report" or become a "Feature Request."