Thank you @wax911, I have already tried to adjust the threshold by acting on these two files, also by recompiling the docker-compose after the modification, but analyzing with mqtt-spy and other listening services I know that the notifications occur anyway with a variable frequency and very not constant.
I use even other device, like the Tasmota sensor, the transmit every 10s and are very reliable.
If you connect the inverter Via RS232 or USB or Eth-RS232 with WatchPower - Lucibus and some other software you can see the variations with a refresh rate of several milliseconds…logically I do not expect to get this kind of results, but already having an update every 5/10 seconds would be very useful in programming the automations.