Sodium benzoate is an organic acid, and also found in G-05. G-05 uses borate as well to protect cylinder liners, while azole is there to protect copper.
G-11 is VW's old school coolant before G-12(G-30) was used. G-48 is 2-EHA.
In theory, all OATs should play nice with each other but not always.
Borate used to protect cylinder liners? you sure about that?
The only use of Borate in a coolant that i know of is that it acts as a pH buffer, it doesn't have any corrosion inhibitor properties that i know of, in fact it's well known to be aggressive towards aluminium.
Also about 2-Eha being present in G48, i do know of one particular G48 coolant made by a brand called AD that doesn't have any mention of 2-Eha , at least in the SDS, other brands like Glysantin do seem to mention it in the SDS.
So what i understand is that G11 uses Sodium Benzoate as the OAT inhibitor and G48 uses 2-Eha and / or something else depending on brand?