My EVC is pre-set at 1.5bar for daily driven, took it to the canyon last night and pulled 1.7 bar, does that mean my boost controller is not holding boost?

 

You need to learn to tune it and make it run the proper boost. The point of spending so much on an EBC is so that you have more granular control over boost. If you don't bother to learn how to use it, then it's a paperweight, and you should have an MBC.

The EBC doesn't "hold" boost - it just controls it. Your boost system and BOV are what "hold" the boost.