485mg/i at idle is expected airflow at idle with egr shut or not operating.
300 odd is what it should drop to when the egr is open or operating.
You have cleaned egr but did you check the solenoid half of the valve was free and operating?
There could also be a blockage in egr cooler/pipe?
Log again when warm , idle only and egr should cycle on /off every 2-3 minutes so 6 min log should see at least 2 egr cycles.
But basically as egr opens the actual airflow should drop to near desired airflow, if it doesnt drop theres no flow through egr.
Sometimes the pin in the solenoid can stick/seize.
edit heres mine a while ago
im not sure why your solenoid is shut(1%) but its still expecting 300's this should be around 485 when it knows solenoids shut.
has your maf got a temp sensor also, do maf temp and map temp look realistic(maf temp should be around ambient air temp+/- a few degrees, map temp at idle probably 10-20 degrees higher than maf temp with warm engine at idle)