Hi, and welcome to the OpenEMS Community!
From experience I can say, that modbus protocols for different GoodWe hybrid inverters are similar. Usually simple charge/discharge commands should be easy to do, but more advanced control might still require significant amount of implementation work.
There are some companies available for OpenEMS contracting, mainly members of the OpenEMS Association. Currently FENECON has the most in-depth experience for implementing battery inverters, but we are not available for direct OpenEMS contracting - only as part of our efforts with FENECON products.
I don’t have any personal experience with the “GW3600S-BP”, but I’ll be happy to support you on your first steps. See this thread for some first advices an implementing a battery inverter: ESS that can talk with OpenEMS using Modbus TCP - #4 by stefan.feilmeier.
Can you provide a modbus protocol? That’s anyhow always the first step… 
Regards,
Stefan