Ha, so it's better to run on the ragged edge close to triggering a check engine light? That's kind of silly, don't you think?
And the JB4 does in fact fool the ECU so certain factory fail safes can no longer protect the engine. A lot of these factory mechanisms rely on key inputs which are manipulated by the JB4. It can't "bail you out" in certain situations because the data it's reading have been altered by the JB4.
If you chasing records or more performance ragged edge is a figure of speech. When is it ragged, when you go past 250-275-300-325 etc. The one engine broke at around 380 so people know now not to push that far.
Not sure which other factory mechanisms it would affect. Boost is increased 1-3psi average over a flash. The ECU's only mechanism for boost is if it goes over target. Since its sees stock boost/flash boost if that goes over it will still save the engine. The JB4 has this built in too with the boost safety value as well as AFR lean protection.
The rail pressure is also altered. This wont affect anything in terms of safety.
The 1.8T was treated like the black sheep by the tuning fraternity and we stepped in and closed the gap and people have gotten years of enjoyment that otherwise they wouldn't get. There is obviously still a gap in the market since some users want even more than the canned tunes available and we fill that gap. There is risk associated and someone is bound to find out the hard way but end of the day the people playing at those power levels are not doing it blindly since they get our support but are also aware of the associated risks. Something similar to you breaking so many axles on your Audi.
In terms of 2.0T there is a large thread on that side that you can go ask.