I'm a little confused by the latest versions changelog. Did they fix the issue with downloading Amazon videos at 1080p, or something else? It states that the issue is fixed when trying to download them with certain audio settings, but does that mean videos will now be downloaded natively at 1080p, or is there some post processing that will upscale the videos?
Dimensional
Yes,  with StreamFab 4.0.1.2  Downloading from Amazon at 1080p has returned, however it was only downloading as AVC(H264) no matter how you configured that Amazon setting in StreamFab,  but we were seeing 224 kb/s, 84 kHz, 2 Channel E-AC-3 (DD+) audio.  On movies where I kept an eye on StreamFab's temp folders while downloading,  the video downloaded by StreamFab before any processing is done   *IS* 1080p.   StreamFab is not upscaling after download to get 1080p.
StreamFab 4.0.1.3 was released.  That fixed it so that if you set H265 for Amazon in StreamFab settings,  it is downloading HEVC(H265) video,  and it also resulted in 640 kb/s 48 kHz, 6 Channel (5.1), E-AC-3 (DD+) audio.  Again, the video downloaded is 1080P and not upscaled by some post process.
I see that 4.0.1.4 has just been released and includes a note about "Fix: A problem that the audio format of the downloaded Amazon Prime videos is not EAC3 5.1"  but I haven't installed or tried that version yet to see if this was intended to fix the stereo audio issue we saw with H264 video in 4.0.1.2 or if they mean something else.