as mentioned earlier above
the maf should be approx 485mg/i at idle and boost pressure should be around 1000mb (at sea level, change for your altitude above sea level, quick google your pressure at altitude)
at idle or free reving the ecu will not be requesting boost but the car will make some just from the speed your reving up at and the ability of the vnt to reduce the boost so you may see boost go to 1100mb or 1200mb or so.
this will automatically increase the maf value, so for example 485mg/i x 1.2(1200mb)=582mg/i
this is a graph of mine doing idle and free revving in steps as example
maf vs revs graph.png
also the above calculation works pretty well for diagnosing things of say you put new map sensor on and boost is 2300mbar take your boost divide by 1000/485=2 so 2300mb/2= 1150mg/i maf
now if your cars showing 1000mg/imaf you can pretty much guarantee somethings amis.
of course it could be maf issue or manifold blockage or swirl flap or split pipe after maf or many other things but the relationship of boost and maf should be fairly constant (will vary with air temp and humidity and intercooler temps etc)
my boost div maf.png
and lastly if your egr blanked and your only reading in the 300s maf you have an issue right there
ps heres hopefully your ve map if not yours should be close enough, revs left column fuel accross top ve % in the table see nowhere is 100% and variations accross the table with revs and fuel.
2.4jtdm ve map.png
so engine can only breathe this % of theoretical 100% so 1500revs better than 3000revs free reving for example by a few percent so at same boost pressure 1500revs would have slightly higher maf than 3000revs with same boost pressure but 4% would barely be provable due to all other variables.