Sonoff TRVZB… SONOFF TRVZB control via MQTT | Zigbee2MQTT
Using Valve opening degree and Valve closing degree you can effectively open the valve to the desired opening %. E.g. setting opening degree to 30% together with closing degree to 70% effectively opens the valve to 30% (both need to be set at the same time).
For example Versatile thermostat integration uses this feature to proportionally control these Sonoff TRVs. I have 6 of them installed in my home, works just fine.