Here's a curious thing that I discovered in a few spare minutes - not useful, but interesting. As is well known PSE contains a cut-down-to-the-basics version of the ACR/LR raw conversion machine. I took a junk photo and mistreated it in LR 5.5, doing all sorts of silly things with LR tools that PSE's version of ACR does not include. There is a dog in the picture, so I cloned him and made two dogs. I applied a Grad Filter, made it very dark and black and white. I threw in a couple Radial Filters and some brushwork. Then I did Ctrl+S to create an XMP.
When I opened that Raw (CR2) file in PSE 12, it opened in ACR 8.0 with all those crazy edits. Of course the editing was not in the Raw, it was in the XMP that ACR read and applied. But I had expected that ACR, being a "lite" version would apply what it could - WB, Tone/Color edits (Exposure, Clarity, Saturation, etc.) and Sharpening/NR - but would ignore the rest, the editing done by tools it lacks. But no, it was all there; the clone, the filters, the brush.
"Old-timers" may remember when, a bit more than ten years ago, Canon released the revolutionary first model of the Rebel line, the 300D. Some bright fellow among the designers had the idea to save time, work and money by giving it the 10D's firmware with the "high ticket" items locked and hidden. It didn't take long until it was hacked and unlocked and Canon learned a lesson. I think Adobe has done the same thing. PSE's ACR is the "full monty", capable of doing it all, but all the "added value" items are not accessible from the UI. Of course having discovered this is of no value whatever - the edited Raw still has to be converted to RGB in order to do anything more with it and using LR's Edit In is faster, but I did think it interesting.

