Re: The Pegasus
The Federation has a vested interest in peace, as has been made clear through the course of multiple series. By that standard it's in their own best interests to interpret the treaty liberally rather than aggravate the Romulans with some bullshit line (even if it were honest), that cloaking is just a "secondary effect".
It was the best of Trek, it was the worst of Trek...
"If I lean over, I leave myself open to wedgies, wet willies, or even the dreaded Rear Admiral!"