If you read Andy's "vindaloo 10 year" recipe thread you will see mention of Msg as an optional enhancer, decision to include it determined by sense of smell (odd). It is not included in the listed ingredients but appears in the method. Also of note is the inclusion of Aromatic Salt, in itself containing trace amounts of up to 6 or more spices. I'd imagine his other recipes contain similar advice.
I was doing same thing Phil.
Chicken Madras has exact same recommendation. Step 6) in method.
He was a big fan of TRS tandoori Masala, asafoetida, the pre-cooked onion paste and Aromatic Salt. Plus Msg. HIS idea of the BIR flavour perhaps.