Thanks, that is a very good question, I suppose in all honesty it cant have done any harm, that said a modular OAT stamp I think would have gone as far as an APP stamp.
In my opinion you pay extra for the APP to get OATs help and guidance whereas when you dont get it you might as well have saved 20k and still have their modular stamp on your cv.
One thing I would say though is having the APP stamp + first series IR etc etc on the CV, still resulted in loads of airlines simply ignoring your cv alltogether......