Take a look at the suggestions in this article: https://www.lifewire.com/stop-alexa-from-listening-5121012
If you disable the microphone, except when you want to use it, that should severely limit what it can do. If you also set the option that tells Amazon not to keep any of your recordings that should keep you fairly safe.
The caveat is that Amazon can decide to cheat at any time. They have repeatedly lied about what information that acquire, how long they retain it, and what they do with it. At the moment, they don’t seem to be cheating on the Echo functions, but that could change at any time with an invisible firmware update. There isn’t anything you can do about this except to be aware of the possibility.
It is definitely worth using the privacy options they offer, even if they aren’t enforced through hardware.
I’ve just been looking for something to replace One Note. The timing of this announcement worked out really well for me. :-)
Thanks!