WASAPI not used even when hard-coded

My setup:

Kodi 17.1
HDMI to Yamama Amp (and then on to a projector)

I have my advancedsettings.xml set to hardcode the WASAPI GUID for my HDMI interface.
I have passthru enabled.
I’ve set the Audio Keep-Alive timer to Always/None/1 Minute and 10 minutes, and I’ve alternated the “Low volume noise” on/off.

I’ve read though several threads and it seems to be a common issue:

http://forum.kodi.tv/showthread.php?tid=…ght=wasapi
http://forum.kodi.tv/showthread.php?tid=…pid1357945
http://forum.kodi.tv/showthread.php?tid=133755

Typically I will startup my Amp (the HTPC is always runnning) and then proceed to start a movie, and typically I end up with DirectSound because the Amp shows PCM instead of whatever the native format is. If I stop the movie and restart it will typically be correctly set to WASAPI after that.

Here is the log:
https://pastebin.com/ZteTG4E0

At 20:26 I start Star Wars:

Code:
20:26:50.436 T:7368  NOTICE: VideoPlayer: Opening: smb://10.0.0.7/movies/Star Wars - Episode IV - A New Hope (1977).mkv
20:26:50.436 T:7368 WARNING: CDVDMessageQueue(player)::Put MSGQ_NOT_INITIALIZED
20:26:50.439 T:7368   ERROR: DXVA::CProcessorHD::IsFormatSupported: Unsupported format 104 for 1.
20:26:50.439 T:7368   ERROR: DXVA::CProcessorHD::IsFormatSupported: Unsupported format 105 for 1.
20:26:50.440 T:5820  NOTICE: Creating InputStream
20:26:50.557 T:5820  NOTICE: Creating Demuxer
20:26:50.663 T:5820  NOTICE: Opening stream: 0 source: 256
20:26:50.663 T:5820  NOTICE: Creating video codec with codec id: 28
20:26:50.663 T:5820  NOTICE: CDVDVideoCodecFFmpeg::Open() Using codec: H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
20:26:50.663 T:5820  NOTICE: Creating video thread
20:26:50.663 T:5820  NOTICE: Opening stream: 2 source: 256
20:26:50.663 T:6332  NOTICE: running thread: video_thread
20:26:50.664 T:5820  NOTICE: Finding audio codec for: 86020
20:26:50.664 T:5820  NOTICE: Creating audio thread
20:26:50.664 T:5820  NOTICE: Opening stream: 4 source: 256
20:26:50.664 T:2180  NOTICE: running thread: CVideoPlayerAudio::Process()
20:26:50.664 T:6332  NOTICE: CDVDVideoCodecFFmpeg::GetFormat - Creating DXVA(1920x1080)
20:26:50.674 T:2180  NOTICE: Creating audio stream (codec id: 86020, channels: 7, sample rate: 48000, no pass-through)

I do it again at 20:27 with the same result, and then at 20:29 I try again:

Code:
20:29:19.368 T:7368  NOTICE: VideoPlayer: Opening: smb://10.0.0.7/movies/Star Wars - Episode IV - A New Hope (1977).mkv
20:29:19.368 T:7368 WARNING: CDVDMessageQueue(player)::Put MSGQ_NOT_INITIALIZED
20:29:19.368 T:7368   ERROR: DXVA::CProcessorHD::IsFormatSupported: Unsupported format 104 for 1.
20:29:19.368 T:7368   ERROR: DXVA::CProcessorHD::IsFormatSupported: Unsupported format 105 for 1.
20:29:19.368 T:6824  NOTICE: Creating InputStream
20:29:19.423 T:6824  NOTICE: Creating Demuxer
20:29:19.480 T:6824  NOTICE: Opening stream: 0 source: 256
20:29:19.480 T:6824  NOTICE: Creating video codec with codec id: 28
20:29:19.480 T:6824  NOTICE: CDVDVideoCodecFFmpeg::Open() Using codec: H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
20:29:19.480 T:6824  NOTICE: Creating video thread
20:29:19.480 T:6824  NOTICE: Opening stream: 2 source: 256
20:29:19.480 T:6824  NOTICE: Finding audio codec for: 86020
20:29:19.480 T:6824  NOTICE: Creating audio thread
20:29:19.480 T:7932  NOTICE: running thread: video_thread
20:29:19.480 T:6824  NOTICE: Opening stream: 4 source: 256
20:29:19.481 T:6864  NOTICE: running thread: CVideoPlayerAudio::Process()
20:29:19.482 T:7932  NOTICE: CDVDVideoCodecFFmpeg::GetFormat - Creating DXVA(1920x1080)
20:29:19.491 T:6864  NOTICE: Creating audio stream (codec id: 86020, channels: 6, sample rate: 48000, pass-through)

This time it works and I had passthru.

What can I do (config/hack/workaround) to get WASAP playback everytime? Is there something else I can do configuration wise to ensure I get WASAPI?