Change default A/V behavior in 2017 head unit?

I just traded up to the 2017 Mirage, and it has the touchscreen A/V. I mostly love it, except for one GLARING problem. I use the Bluetooth for my audio needs, and every time I get back into the car, it decides what I really want to do is to listen to the godblessed FM radio at full volume instead of waiting for the Bluetooth handshake. This wouldn't be such a deal, except that I'm in and out of the car probably 50 times a day.
I'd REALLY like to figure out a way to change this. I suppose there are workarounds, like buying a cheap iPod and plugging it in, but then I'd have to manually load podcasts and playlists and such every day. Which I'm not about. This is the freaking future, I want my pocket computer that self-updates to have control of my car stereo. Like my 2014 did.

Leave the phone & keys in the car. Doesn't seem to lose the connection, and boots right back into BT

Finally, someone like me!

It wouldn't be such a huge issue if the Bluetooth audio wasn't substantially lower in volume than the Radio or CD output. I use Android Auto in my Mirage, and if the USB cable disconnects for any reason (which I was having trouble with a specific model of phone randomly doing so), the head unit would immediately switch to the next input, which is the radio (and blast me to death).

No, there's no way to fix this. I've just made it a habit to always turn off the radio before turning the car off, so it's never on when I start it. I've found the hard way that when the head unit is still booting up (Mitsubishi logo on the screen), you actually can't adjust the volume or even shut it off, so I hope you didn't have it turned up previously!

One trick you might try is burn a CD with nothing but silence, and put it on loop. Hopefully it'll switch to that input first instead of the radio.

Yeah... the Hyundai built radio LOVES to do this... I've learned to shut the radio off before turning the car off as well.