@Ryan @Bill C.
I have the same system, it has been up and running for over a year. Connecting devices is pretty straight forward. I have my REC and WS500Pro connected to the VE.CAN ports on the Cerbo GX. Make sure all the firmware for the components are up to date and the CAN baud rates match (250kbts). To make changes on the REC, Use the wifi module web interface and go to the firmware tab. Make sure it is unlocked and scroll to the bottom of the page where it says "Manual communication"
In the first box, "Address" - select 2.
next box, "Message" - type "CANS?"
next box, "Response" - You should see a number 0-4, This corresponds to a baud rate, 2 being 250 kbs
To make a change just type "CANS 2" this will change the baud rate to 250kbs
The Wakespeed default baud setting is 250 kbs but that is easy to change with the app if needed.
I just upgraded my WS500 to the Pro model and ran into some problems setting up the Pro. See my post https://ogm-energy.com/community/ogm-user-forum/topic/153136/ws500-pro-unable-to-connect-to-abms
Wakespeed is working on releasing a new firmware for the WS500Pro. If you need help now, you will have to reach out to Wakespeed directly to get a patched firmware. This will allow the WS500Pro to sync it's CAN bus signal with the REC ABMS' CAN bus signal via the Cerbo GX. They are very helpful and quick to respond to requests.
I hope this helps.
-Rance