However, we are ignoring the GIANT Elephant in the room here, which is really annoying.
You use a Bluetooth speaker.
The speaker is turned off, then you can ask the Echo to pair to Bluetooth, it will search, find the speaker and flip it's audio from it's only little internal speaker to your Bluetooth one.
That's Great
If you don't wish to use your Bluetooth speaker all the time, all during the night, when you are work etc, you turn is off and the Dot reverts to it's own internal speaker again.
That's Great
However, and this is where the large Elephant makes its appearance.
You use a wired connection for better sound quality and the second you physically insert the jack plug into the Dot, it's speaker is killed dead, and will stay dead, irrespective of your Amp/Speaker, until you physically pull the jack plug back out of the Dot.
Major pain/fail from a usability/practicality standpoint.
What they SHOULD have done ideally is to not kill the internal speaker, but allow a voice command to either use internal speaker, or use external speaker.
They have done it the cheap way that little radios etc have used for decades, the physical bending of pins in the socket, kills the built in speaker.
Shame as it really makes using a wired connection much more of an issue.