I was already on another thread posting about notification issues on the duo. And I thought I’d swing by and do a quick update. I got the door chime controller in today. It’s pretty cute. I didn’t realize it was so small. Glad it is though, for easier installation. I’m assuming it is some sort of solid-state relay or micro relay setup. We’ll see once I install it.
I tried the digital doorbell option this morning. Starting all the way at 9sec, then to 5, then down to 1. That worked like expected. Not ideal and would be asking for some electrical issues down the road. Ultimately, I settled back to the mechanical setting (for now) after giving it another try. When I first tried it last week it wasn’t working correctly with ‘mechanical’ set. It wouldn’t fully ding and dong, like the trigger was way too fast for the plunger to actuate - so it wasn’t loud enough. Today, however, it gives me a full ding-dong 
…uh… it’s still a little too quick, I think, but it hits both plates (the ding and dong plates).
Buuuuut, it still has a very slight electrical hum that can be heard when everything is quiet. Almost in audible. ‘older’ ears may not even be able to notice it. It can also be felt when touching the plunger, which when done, makes the sound go away - the sudden dampening/removal of sound lets you realize it was there, kind of thing.
Before installing the chime controller, I want to test the hum (by listening) up at the doorbell itself, to see if that may have changed. But, it’s pretty stormy right now, and the outside ambient noise outside it crazy! 
I’ll update on here when I can. 
Here’s a picture of my actual doorbell for reference… ya know the mechanical ding-donger. A super simple setup only one ‘doorbell’ -the front door
Note: Wyze should have had me (and many others) help beta test this doorbell a bit more.