It's a "standard" LUT printer profile operating out of LAB PCS. And that's about the only thing that makes any sense.
I'm able to examine the profile with Profile Inspector from color.org. This is the most insane profile I've ever seen! There are 10 points on each axis for the AtoB1 tables and 62!!!! points on the BtoA1 tables. OK, that's pretty weird, but get this. The media white point tag has Y at 1.15. That is simply crazy. 100% reflectivity is Y=1.00 (L*==100) and most media comes in between .85 and .93.
My guess is that Photoshop grays out the view paper white because it is outside any real life range.
You might want to consider making profiles with Argyll. It works. It's free.
Hmmm. seems pretty weird, even if I don't know what AtoB1 and BtoA1 are!
Crazy thing is of course, that the prints look pretty darn good and match the softproof very well. (of course without the paper white preview, but I keep my display down to 60 white level when printing.)
I've looked at Argyll, and it looks, to me, like a big challenge as I'm not familiar with working with the command line interface. So a pretty darn good learning curve here. I do use DisplayCal though for display calibration for video and even with it's GUI, the documentation is confusing as .... heck.
Anyway, all is pretty strange as the EFI software has so few settings to choose from when making a profile, it's hard to believe it just doesn't make a correct, though simple, profile.