I just found an app called "MPO master" that converts .mpo directly to side by side. Or anaglyph if you like. You can swap sides for cross-eye viewing.
Previous apps I've had only converted the .mpo to seperate right and left images, which I had to manually combine into a single jpg for viewing with Whirligig.
Cost me less than $3us in Microsoft store.
I have a Fugi W3, but it's discontinued and I hope the onslaught of WMR devices will lead to the production of new stereo cameras. Being able to actually view the pictures in stereo in the Rift or other hmd makes it more practical.
i7-5820K @ 4.2Ghz, water cooled, Asus X99-Pro USB 3.1, 48 Gb DDR4 2400, Samsung 950 pro M.2 SSD, GTX 980 Ti SC, 750w psu