Is there a way to validate this in PS
You can easily tell in QU. Mouse over the thumbnail in QU, the exif data and profile show in the "Exif hotbar" below the thumbs. If the profile has asterisks before & after, it's embedded.
If it's not, QU may default to sRGB. With Jpegs from a camera, QU will read the exif tag sRGB or Adobe RGB. You can override the indicated profile, where you know for sure what the image colour space is, in the image editor where no change is made to the image but it's made by a "filter".
As i understand you are recommending I bring the image in QU without any output sharpening in PS and let that be handled via QU algorithms. Right?
Yes.
What do you mean by automatic resize. I did not get that part?
This is fundamental to the way QU works because it resizes an image as it is sent to the printer to the native resolution of the printer, 720ppi for Epson, 600ppi for Canon. QU reads this from the driver. This process avoids the driver doing any interpolation and the QU interpolation algorithm (Fusion), which is a world beater, has control. This also means only one interpolation is recommended in the process so any re-sizing prior to printing in QU will degrade the print.
See the second link in my previous post.
Hope that helps to make things clear.
Terry