What photo editing software will keep tags (incl. face/people tags) with the file (EXIF/XMP)?

I am evaluating Photoshop Elements and Lightroom for my photos. I store my photos in the cloud (currently OneDrive) and on a website (currently SmugMug). At the end of every year I like to go through the photos for the year on my laptop, organize the photos into folders, and add metadata to my photos including a description, tags, and face tags. After I am done I put them up on the cloud and they will no longer be on my laptop. I am looking for software that will make it quicker for me to add metadata to my photos than my old approach (Windows Live Photo Gallery) and will allow for the workflow defined above.

I desperately want the software I use to store all metadata within the JPG file itself. This is what EXIF is for! I realize that face tags are not part of the EXIF standard, but understand that face tagging is part of Adobe’s XMP “standard” (Is there an EXIF standard for tagging people in photographs?). I want all of my photos to be portable to whatever location I choose so that I am not bound to any storage service or image editor.

I see that Photoshop Elements by default stores the user added notes/description to the file, but does not by store much of the metadata in the EXIF properties such as title/caption, tags, or face tags. However, I did discover that the “File > Save Metadata to File” menu option does save title/caption and regular tags. However, face tags are still missing. Does anyone know how I store face tags to the image file with Photoshop Elements? If not Elements, would Lightroom or some other software do this for me?

I see that Picasa (which I once tried and stopped using for this same reason) now may have the ability to export metadata: How can you write/convert Picasa's People tags to the EXIF data?. I’d like to stay with Elements or Lightroom (I’m undergoing a trial of both right now), but this problem needs to be solved or I won’t use them.