Alexxit Home Assistant add-on makes it possible to get Sonoff stats without flashing Tasmota. This is done by using a second Ewelink account.

If your Sonoff Pow2 just stops getting data, make sure you are using cloud only mode. My IOT devices are on a separate VLAN and seems it stops gathering data after a while.

https://github.com/AlexxIT/SonoffLAN#local-and-cloud-mode

sonoff:
  username: xxxx
  password: xxxx
  force_update: [power]
  #scan_interval: '02:00:00'  # (optional) default 5 minutes
  sensors: [power, current, voltage]
  mode: cloud
  reload: always
  devices:
    10013xxxx:
      reporting:
        power: [60, 3600, 1]  # min seconds, max seconds, min delta value
        current: [60, 3600, 1]
        voltage: [60, 3600, 1]
    10013xxxx:
      reporting:
        power: [60, 3600, 1]  # min seconds, max seconds, min delta value
        current: [60, 3600, 1]
        voltage: [60, 3600, 1]
    10013xxxx:
      reporting:
        power: [60, 3600, 1]  # min seconds, max seconds, min delta value
        current: [60, 3600, 1]
        voltage: [60, 3600, 1]
    10013xxxx:
      reporting:
        power: [60, 3600, 1]  # min seconds, max seconds, min delta value
        current: [60, 3600, 1]
        voltage: [60, 3600, 1]