A former FAA Chief Counsel under oath once referred to the FARs as "a monument to vagueness."
My operating limitations are in the hangar and I don't have an electronic copy at home, but I do have a copy of "Example of New Operational Limitations," the new one size fits all operating limitations -- it includes things that really only apply to Eastern European warbirds, like life-limited components for example. I'm relatively confident that these are my operating limitations...
It says, "2. These operating limitations do not provide any relief from any applicable law or regulation. This aircraft must be operated per applicable regulations and the additional limitations prescribed herein."
And it quotes 91.205(c), for night VFR, and (d), for IFR, but not (b), which is for VFR aircraft. (b) includes, "(3) Magnetic direction indicator." That does not state explicitly that it must be a whisky compass.
But here's the kicker, the applicability -- 91.205 - Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and equipment requirements.
As the old saying goes, consider what your actions would look like on the NTSB accident report...