Poll Pylontech Battery BMS via RS485 & publish via MQTT - Python

I require a python script written to run on a Raspberry Pi that will poll data from a Pylontech US2000 Battery BMS. ICD attached. Batteries are linked together but can each be polled from the master battery.

Script will be used as part of a home automation system sold to users of Pylontech batteries. Data will be displayed using NodeRed/Home Assistant

script shall run on a Raspberry Pi
script shall have comments written in english
script shall be written in logic structure so allow third party to make changes at later date
script shall connect to the battery BMS via an RS485 connection.
script shall poll for Live data every x seconds
script shall poll for static data every x seconds
script shall publish live data via MQTT
script shall close tty port once poll has finished to allow other scripts to access port.
script shall read system config data from a separate config file
Config file shall allow MQTT host address, MQTT server user:pass, MQTT server port number to be specified
Config file shall allow the poll & publish frequency to be specified
Config file shall allow which parameters are polled.

WIll make Raspberry pi available and or windows PC available for remote testing

Proposal shall include list of items that can be polled and also include minor bug updates.