JSON-LD streaming document still mandating buffering the full file

JSON-LD content often use the layout following layout

{
   "@context": {...},
   "@graph": [...]
}

where @graph content should be in the default graph whereas in

{
   "@context": {...},
   "@graph": [...],
   "foo": "bar"
}

@graph content is in the named graph.

If I understand properly the JSON-LD streaming document, the parser have to buffer the full file to check if there is no @id or other key at the end of the file (in my example foo).

Am I correct in this interpretation?. If yes would it be worth it to make a new version of the JSON-LD streaming document that would mandate that the @graph key is always the last?

Start with the JSON-LD streaming document and compare its processing rules against the two @graph layouts shown in the issue. Verify whether determining the graph requires seeing later keys, then document the conclusion and any agreed change to the streaming specification.