Seth:
In the four large organisations I have worked in since 1971: Canadian Department of National Defence, Standards Council of Canada, the Canadian Association for Laboratory Accreditation, and Exova Lab Group, only the first three allowed the use of private aircraft as a method of personal transport for business trave. Exova's brokers were scared so, with the tacit agreement of my president, I simply charged the equivalent of car mileage and they did not care.
Now that I am the owner of my own company, and I am using the aircraft for business travel, I will expense gas, parking and other things as part of my own business costs - so this is no longer an issue. Maybe more so long as I avoid hassles from Transport Canada on the "for hire or reward" aspect of my use of the aircraft until I get my commercial rating.
But...and this is for the fight you are considering, I provided Exova, their broker, and their underwriters with the standard forms (statements) made to the other three organisations to indemnify them for my own use of the aircraft while on company travel and it made ZERO difference. It turns out that private organisations (unlike the two government ones I was in before) are scared of insurance companies and these decisions are all personality dependent. Fear based decsision making will, in the end, not result in going back to the way things were before for you. Wish I could tell you different, but my experience says that is how it will likely come down.
BTW: Congrats on the new set of wings. As well, I am not going into Gaithersburg, but Indian Head on the week of the 18th. They changed the conference venue - but thanks for the offer of assistance.