"What rules, regulations's and processes and procedures do we need waivers for, in order to do this FIST thing?"
I have to admit, I'm always a bit confused by that question.
See, FIST is a set of values that is designed to influence our decision making and organizational behavior. It says "It's important and good to be fast, inexpensive, simple and tiny." There generally aren't any regulations or requirements that forbid such a stance. Sure, some rules and reg's are less than helpful, and some interpretations of rules point us in the opposite direction of FIST... but in the latter case, it's generally because our values are pointing in that opposite direction anyway!
The bottom line is that FIST can be applied under just about any framework or set of guiding policies. Strictly speaking, no waivers are necessary and nothing is really stopping us from opting for the faster, less expensive, simpler and smaller option. Having said that, FIST can also be applied TO just about any framework or set of policies. We could simplify, shrink and accelerate our policies - I think that'd be good for everyone (because I think the FIST values are good).
And yeah, I'm sure just about every technology development environment has some policies, regulations, etc that are un-FISTy. But do you need a waiver or some sort of official permission to make decisions these ways? No - if you're making design decisions (about documents, technologies, organizations, etc), you can make them with FIST.