This is my clone of repo https://kellerza.github.io/sunsynk/ which enables to run it as a second instance with its own MODBUS device settings. Spcifically it was designed to control a heatpump with register specifications in mysensors.py.
DISCLAIMER: Use at your own risk! Especially when writing any settings.
Refer to https://kellerza.github.io/sunsynk/ for detailed information.