I did have to replace my rings shortly after the turbo install but I don't directly link that to the blue box. It may have attributed to the ring failure but my rings were on their way out since I bought the car.

The VAFC is good for minor mods like cams and stuff. It won't read boost, it isn't fine tunable, doesn't tune igntion timing, and the OBD2 program will learn around it, so it isn't a good thing to use for a boosted setup. A stand alone ECU is the best bet for a boosted OBD2 application.