Water meter / Pulse Counter with Sonoff Basic R2

Hello from Sunny Madagascar!
I recently received a water bill that would have made your eyes water!
I have purchased a 10L/pulse water meter with an analog readout (see picture), so I can get to the bottom of what is causing my water bill woes.
I have some Sonoff Basic R2s and DIY Minis , so can I connect the pulse output wires from the water meter up to GPIO3 or GPIO14 (switch input on Mini) to count the pulses? Or, should I use something like an ESP32 so that the board is not mains connected?
Lastly, which firmware is best for this project, Tasmota or Esphome?

ESPHome is far more flexible but for pulse counting either would do.

Metal plumbing should be grounded and the pulse outputs should be isolated but there’s no penalty for erring on the side of caution and powering whatever you use from an isolated DC plug pack.