P: Priority photo in photomerge

As a wedding and portrait photographer, I frequently do quick two shot(sometimes 3 or 4, but that's besides the point.)portraits to stitch together into a square image.  I generally do two horizontal images, one full length, then one ~shoulders up and getting the sky/background.  My issue is that humans blink and make goofy faces all the time... and Lightroom seems to have gotten better and better at picking the worst possible option when merging a panorama. Is it really too much to ask  to be able to select a "priority" image when making a panorama?  I know I can jump into Photoshop and have all the control I need, but that takes more time than I want to spend... I have to shoot and edit thousands of photos every week and moving between programs slows down my workflow too much.

[Moved to ideas by moderator]