After seeing the Malik videos before I've since thought oil has a big part to play. But the oil that's in your base and a fair bit too. Oil does add to the taste for me, last curries I made I used oil from the base, mixed it with some oil I used for Pakoras and popadoms and added some chili oil all mixed in a bowl and used that for making the final curry, but ultimately I would like to try the following one day.
I think it can be done at home, but you will have to eat curry all week maybe longer.
Example, make a base, use around 60-70% of it then make another base and add the remaining old base and continue and after many changes you should have some well spiced oil in that base and into your dishes. A constant base out on the stove and making allot of curry, or I suppose you could throw it away each day but that's just cruel, maybe freeze a bit each day.
Just writing this reminds me, it's a bit like keeping a fish tank healthy, anyone whose kept fish may relate to that, you just can't start a fresh tank everytime you clean it, the water needs to be chemically matured and balanced.