I doubt that. Soft proof converts to the soft proof color space and that’s send just into the regular pipeline to show images on the screen. See Soft Proofing - #27 by George and read the comments under the diagram.
Maybe when perceptual is used the result might be the same, but non perceptual on the first conversion is changing the input of the second conversion.
From what I read in the manual PSCA is part of the demosaicing process in the standard preset. I don’t see any reference to the export, yet 
George