Just an update to this topic... PLP works now.
Not sure why it wouldn't work for me before, but anyway with the current version AMD software, on my system PLP works fine now. I was able to mix and match 4k 1440p 1080p in various rotational orientations and it all works together in any combination. You do your arranging and orientation of displays in windows settings, then open up eyefinity and it spans them together fine. Super easy.
The one annoying thing is if you have say 5 screens and you only want 4 stitched together.. you have to physically unplug the 5th screen, then run eyefinity automatic config, then plug in the 5th monitor afterwards. I could not get the "manual" eyefinity configurator to do anything for me, but this unplugging method works fine for 1 span. I would like to have been able to do 2 spans top and bottom, but so far no luck. All ears to anybody successfully doing that..
Also it seems to choose screen alignment based on the window positioning, so if you don't like where the black bars are located, you have to kill your eyefinity span then rearrange in windows settings, then rinse repeat. It seems to position the black bars either top, center, or bottom. Not exactly pixel for pixel where they should go. Auto mode sets the height to lowest common pixel count. For example if you place a 2 side 1080p screens in portrait and a center 1440p in landscape, then your height obviously would be 1440p. With black bars on the 1080p's.
Have not messed with current Nvidia software, but will give that a shot when I have time.