Oh! Now the button is there! I'm on the dev channel and downloaded today's image. Maybe the bug fairy saw this post and fixed it last night.

It looks like it has hung trying to import the two images in my gallery. I will log that bug if it doesn't finish.

@ziggutas Just done that ignore the adb error message if you get it and if yours like mine is wifi you will need to pick ut yourself. Installer keeps picking LTE.
Now for the waking up bit. Mine has stopped the wake up thing. It might be down to it being on the original edge channel not sure. Moved back to dev with the edge merge. Now I had forgotten the wake up thing as mine doesn't as I said. Had it up and running now for half an hour on power and still no odd wake ups. Its currently on 2019-12-23.

Edit: When not on mains power I still get the occasional wake up. When on mains nothing. Might be worth someone else trying.

So Release Candidate is halfway between Dev and Stable, I assume. I will stay on Dev for the moment. If I get frustrated, I'll try RC.