My post was confusing, sorry.
It does not activate automatically. I manually activate using the starlink and activate it... this gives me a chance to make a decision about whether I really need internet or not. My router auto swaps to WAN 2 if WAN 1.
My router sends me a local notification when my home internet is down, so I can make a call to activate it pretty quickly. Luckily I've only had to use it a few times when they cut fiber lines in my neighborhood. It gets more use at campsites.
Adding some context:
-I keep starlink connected and powered up, but with service deactivated (unless I used it during that month on a trip). It downloads updates and does it's thing in the background.
-If fiber internet goes down, I login to the starlink app over cell network or direct connect to starlink router and reactivate service for a month.
-Service isn't prorated, so once I pay for a month I'm stuck with it. I have a mini, so monthly service is $50 for $50/gb + $1/gb over that.
-To save bandwidth, I explicitly disallow many devices from connecting to WAN 2.
This is overkill, but I work from home most of the time and not having internet kills my day. It's also peace of mind that I have a reliable internet source beyond the life of my UPS when the power goes out.