How can I force Ok Google to use speaker when connected to bluetooth?

[AC Question]

There is the fairly common problem that many people have that services like "Ok Google", Google Maps navigation, and other TTS services output their audio via the A2DP "media" bluetooth profile instead of through the "HFP" bluetooth profile. What this means is that, for many car stereos, you need to manually change the mode on your car stereo to the bluetooth input channel, rather than having the phone audio overlay over whatever you're currently listening to, like it does in hands-free mode for things like phone calls. This doesn't really make sense for things like "Ok Google" and Google Maps as the audio is sporadic, so forcing the user to switch to a dedicated channel to hear the audio is incredibly burdensome.

I discovered a solution to this in the form of an Xposed module called AudioBT, which reroutes this audio through HFP, which is great... except that my car does a really poor job at handling the hands-free interruption. In fact, rather than just lowering the current audio output and overlaying the new audio (like it did in my previous car), my car does a full mode switch to "telephone" mode, and then switches back, which takes about 2 seconds each way and is totally unacceptable.

So... what I'm looking to do now is just use the speaker on my phone for all "Ok Google", Google Maps, and other TTS audio. Google Maps already has a "Play voice over Bluetooth" option you can disable, but "Ok Google" does not. Soooo, does anyone know of a way to force "Ok Google" to output to the phone speaker without using the sledgehammer and just fully disabling the "media audio" bluetooth profile?

Thanks!

 

[Rukbat]

As you said, OK Google is hard wired to use the speaker, so you can't use software to insert itself into the app and redirect the audio, unless you have the source code for the app. And I doubt that anyone but Google does. Maps was written with the option, OK Google wasn't. Maybe if the Maps people talked to the other team it would get added (or maybe it would be dropped from future versions of Maps).