Looking at the recipe in the link and DPR's, there is a lot of similarities. I am beginning to think that DPR's recipe only fell short for the amount of base he uses. I also think that it might be better to replace the tomato puree with fresh chopped tomato.
The more I think about it, the more I realise that the taste I am used to, resembles the IG Spice Mix very closely indeed. I know the IG base is very loose and will help to keep the sauce loose as well.
Now I wonder if BIR add coconut flour to it. This seems to make sense, I think I am going to to try some side by side recipes. A good prawn puri is almost as good as a good onion bhaji.