Guidance for Moving over From Google Nest

Hi --

I'm moving over from Google Nest secure, and I wanted to understand what I can use/reuse from that platform. I have a pretty significant amount of investment, so anything I can reuse would be great:

• Google Secure Keypad - assume nothing here.
• Google Nest Window Sensors (https://www.amazon.com/Nest-H1100WES-Detect-White/dp/B076B9CVD2) - these still show up in my Nest / Home app, and they're all nicely working. 
• Yale x Nest Door locks (https://store.google.com/product/nest_x_yale_lock?hl=en-US&pli=1) - Both of these show up in my Nest/Home app. I'd like them to continue to disable the alarm on entry and be lockable through the Simplisafe app.
• Google Nest Smoke Alarms (https://www.amazon.com/S3000BWES-Protect-Carbon-Monoxide-Battery/dp/B00XV1RCRY/) - still show up in Nest/Home app. Do these integrate at all?
• Google Nest Thermostats (https://store.google.com/product/nest_learning_thermostat_3rd_gen?hl=en-US) - assume no changes here?
• Google Nest cameras (https://store.google.com/us/category/nest_cams?hl=en-US) - currently still works. would love to have it come over to simplisafe. 
• Google Nest doorbell (https://www.amazon.com/Google-Nest-Doorbell-Wired-Streaming/dp/B0B1W8WTJ2/) - provides video and doorbell functionality.

Do any/all of these work with Simplisafe? How "integrated" do they feel?

Also, functions of Google Secure I'd love to replicate:

• Auto enable alarm when all phones have left the house
• Multiple users in the Simplisafe account

Thank you so much!