“Be Selective: Never adopt a Standard in its entirety, unless you believe it’s a 100% fit. Instead, you’re best to select those parts which you believe can be integrated into your company culture, with the least disruption to your project activities.”
Actually I believe that should be printed and wallpapered in entire office at the very beginning of every implementation of new project management methodology (and any other too).
I don’t believe you have to use every single practice written in the standard to be successful. I don’t believe there are techniques which are 100% mandatory and you’ll fail when not exercising them. That’s bullshit.
As far as you have any other method to deal with source of the problem, let it be quality of the code or anything else, and it’s aligned with other techniques you use/plan to use things should be fine.
I wouldn’t advise you to stop using your most powerful practice only for not being a part of the standard you’re trying to implement. Whichever methodology you’re going to implement – be selective.