I think either someone's mislead you or you've mislead yourself about how VAG ECU's work wrt to fuelling, boost and timing.
You're suggesting that Revo/APR etc would map a car to the point of catastrophic failure, such that tiny differences from one car to the next would blow one engine up (excluding the fact that the ECU adapts). Either that or actually WANTING your custom mapper to push your map to the edge of catastrophic failure?
With Revo and APR you can actually fiddle/control the timing and boost yourself, so you could argue that your have more control with these generic maps than you do with CERTAIN custom maps. Other custom maps, aren't actually all that custom anyway.
ANYWAY, like you said, each to their own.
If your mapper can scale to the different MAF housing, try it and see. Like we've both been saying, talk to your tuner about what he can/can't do.
A lot of the big turbo boys (IHI's etc) upgrade to the TT225/LCR/R32 MAF and run 340-360bhp. So your standard MAF isn't going to be a restriction if that's what you meant.