SO after watching the new PC edit with Torin in it, I have come to the conclusion that flow and style are much easier with softer boots. This is because there is more natural movement so things don't look out of place. If you watch TWall, Harlaut, and in the newest example, Torin, you can see how they can really crush their boots. It only makes sense that more/easier movement in your legs will allow better natural movement.
There is also another thing I noticed where people like Bobby brown, Nick Goepper, Alex Schlopy, etc who use very stiff boots definitely don't match the style of people who use softer boots. I know there are also many variables to include especially with making comparisons of skiers, but I definitely think there is a large role in how soft a boot is to how much you can define your style.
I personally want to see people like gus and Nick and Bobby ride a few days and make an edit while wearing soft boots to actually confirm my theory.