The router polling integration is probably a bit superfluous for devices that have the companion app installed.
Although, it's still helpful for other devices like guests' phones, or non android/ios devices.

Not sure how helpfully to your use case these will be, but a few ideas...

It's been a while since I tinkered, but I think you can also assign multiple devices to a person and track the person's presence instead of a specific device.
You can also create a group of persons, which is handy for some use cases.

As an example, I have a group.us which contains person.me and person.mypartner. The group's status is home if either of us are home and only changes to away if neither of us are home.

Similarly, I have a group.guests which contains guests who sometimes spend the night.
If any guests are home, my goodnight automation ignores the bathroom and the guest bedroom lights.

group.guests:

entity_id:
  - input_text.manual_guest_tracker
  - person.guest
  - person.fren
  - person.otherfren
  - person.olefren
  - person.stepbro
  - person.nephew
  - person.cousin
  - person.niece
order: 3
icon: mdi:bag-carry-on
friendly_name: Guests

I have an input boolean that changes input_text.manual_guest_tracker to home/not_home if we wanna enable "guests mode" without having to track a device.

Single person with multiple trackers:
person.fren:

editable: true
id: fren
device_trackers:
  - device_tracker.applewafren
  - device_tracker.iphonefren
friendly_name: Fren