If you like the idea of asdf, I would recommend looking at mise. It does all the same things (and more) and is much more performant in my experience.

I set up a notify group for each of us. I use notify.me and add/remove the devices as needed.

notify:
- name: me
  platform: group
  services:
   # - service: mobile_app_pixel_2_xl
    - service: mobile_app_pixel_6

- name: her
  platform: group
  services:
    - service: mobile_app_iphone

Then you can use it like any other service:

service: notify.me
data:
  message: Test
  title: Alert!

It's probably a bit late for a new ESP32, but if not I'm a fan of the M5Stack Atom Lite. It's a solid little device and comes in its own case.

I have been trialing pacdef recently. It sounds like it would do what you're looking for.

I just used your post as a prompt, don't shoot the messenger :)

ChatGPT responses: (probably stolen from some other presentation):

"Connecting Diverse Minds, One Federation at a Time: The Fediverse – Where Decentralization Sparks Unity."

"Decentralize, Unify: Fediverse – Where Connections Flourish Beyond Boundaries."

The Home Assistant team publishes the analytics they collect (for those that allow it). The integrations and add-ons pages might interest you if you haven't seen them.