I also have an E-M1X, what appears to happen is that the thumbnails are initially displayed in a quick to process default way but are subsequently updated by a background process that seems to apply a DXO profile. The thumbnail images become brighter and a little sharper after the profile is applied.
If I select one of the thumbnails for processing, it appears in the main window in its quick display default view with a circular rotating dots marker in the bottom right hand corner while the profile is applied and then displays in its default corrected form.
As I apply corrections to the selected image these are reflected very quickly in the corresponding thumbnail.
Personally, I’m happy with the current process because it means that severely under or over exposed images will be corrected in the thumbnail view so that I can see what each image contains without having to view it in the main window.
With regard to “green shift”, I’m fighting that a lot of the time with my birding images, which, for obvious reasons, tend to have a lot of green content. I use auto white balance on the E-M1X so perhaps I should switch to a fixed colour temperature instead.
I opened a couple of images in both DXO and PhotoShop / CameraRaw and they appeared to have similar colour balances.