"If the mod is enacted it must be tested and documented thus maintaining the airworthiness trail."
In the specific cases for Urgent Operational necessity - I rather embarrasingly disagree.
I would quote the successful "Bodge-Tape and Bean Can" AAR Modifications of Hercs and Nimrods for the Falklands campaign, where an urgent mod was needed and devised (though not designed) by physical trial and error.
These "STFs" were then removed AFTER the conflict and properly designed and supported by OEMs.
This function IS catered for in the MAOS regs (as it is in EASA) but you need to know where to look and how to translate it.
The STF is the fit-for-purpose bit (I call it Mission Capability) and the Safety and Airworthiness bits come in when the STF is inhibited or removed as it is no longer an urgent requirement.
Though the STF can't remain installed indefinately - It can be used if NEEDED, and not just wanted.
Tourist,
If you write what you mean - I may not be such a pedant.
As some sort of aircrew, you should know something of the CRM character type you are portraying in this thread.