OK, so got the new pak file loaded on today. I did ask about the pricing after Shrunk got his done for $145 but got the expected BS about $60 for the pak file (wtf!!), 2hrs of labour etc etc. Total cost was $250 all up so not too bad.
It's a proper reflash of the ECU so nothing is lost if the battery is disconnected. The timing was adjusted by 2 degrees and it seems like it was enough to take out the annoying pink.
Shrunk is probably right in that it's not making any more power, but what power is there, is now accessible. Previously I'd have to ease off on the throttle when the ball bearing started rattling, but now she pulls good and hard all the way through with no sign of pinking. Nicer to drive and no doubt much better for the prolonged life of the engine. A dyno tune might have found some more power, but that's at least 5x the price of this option.
Chucked a can of upper engine cleaner through and now she's good to go.