Well, you cannot declare war on corporate aviation without sending in the troops. The IRS are the initial shock troops.
But I would not worry too much about it, time after time it has been proven that usually high dollar corporate tax attorneys beat the IRS attorneys.
That's because a lot of corporate tax attorneys are former IRS agents or attorneys.
Back when I ran a corporate flight department after I left the government we were audited by the IRS. Our attorneys claimed that, I think, three trips were 'misclassified' and adjusted the return for that particular period and that was the last we heard of it. However, the owner of the company did pay for a lot of his trips claiming that there were personal. I was told that flight departments that claimed a near 100% usage of the aircraft were audited the most often.
Oh, I did know of one company that claimed 100% business use. The flight crews never flew on weekends or holidays that I knew of, they shared hangar space with us. They had great documentation, but the IRS refused believe all was business use, so the company compromised with the IRS and paid a very small tax penalty. After that, they started flying person use trips, figured if they were going to have to pay for personal use when they didn't do any, might as well do them and pay up front.