I'm not sure. Dimitrov and Tito wanted to form
Balkan Federation, but they didn't quite agree about the leadership and Macedonian question. My impression was that Dimitrov was always following Stalin's policy, and that he opportunistically wanted to grab parts of Macedonia for himself, but when SSSR sad
No (for different reasons) he just stepped out of it. Didn't get the impression that he was acting as anybody's agent.
As for Greeks, it was time when Markos Vafiadis (who was cooperating with Tito) was ousted from the Communist party, so that initiative could be made that Aegean and Pirin Macedonians together with nationalistic forces from Yugoslav republic of Macedonia could start a chaos that would overthrow Tito.
the story of Greek resistance and Greek communist party is full of such,
the personal story of Zachariadis is quite enough to understand the agents and how they worked,
I am not telling that Tito was good, or vafiadis was good, or Stalin was good,
I am telling that from 45 -55 the area was full of agents, which all act for foreign powers, outside balkans,
historically if you notice, Dimitrof, wanted to mix again the soup for new civil wars to open.
communist party was famous in Greece reaching numbers like 30-45% at 1945 in North Greece,
but the stand that Dimitrov proposed drop it to 4-5% lower than every working class than southern Greece.
he promised tremendous Soviet Help to Partisans, and all he did was to return to Moschow,
he manage to divide the communist party mentalists of Athens with the armed partisans in North Greece and expell Zachariadis,
he first tell not sign Varkiza, and then proposed the disarm of partisans,
if you understand his 'work' you realize for whom was acting.
same is in Ukraine and Moldova,
agents from both sides, all promise 'good days' but poverty and war instead of help is coming,
yesterday was a big NATO/OTAn congress, do you see any fast or catalytic desicions? I did not,