Hi DLMB, from what I know about the ARK 2.5L CAN is that in one of the IDs is responsible for the battery type and its software. It is totally possible the 5000ES Firmware to check the battery type and reject it if it is not acceptable...or what I know about 5000ES is that it send a constant string to the battery, may be the battery BMS check if the inverter is from the supported type and switch power to the terminals.
If you can ask Growatt service to provide gbli6532 protocol (or confirm if it is CAN 1.05 like the one used in ARK, L51 in menu 36) then we can proceed further and make a plan how to fool them to work together...
...I just checked the gbli6532 is advertised as CAN 2.0 protocol, that means for sure wont work with supported L51(CAN 1.05) by the 5000ES.
Anyway if you can get the CAN 2.0 protocol specification from Growatt support, please share it with me, I can develop some kind of gateway
b/w 5000ES and the new battery.