What about clients who "want that one feature that isn't present currently but you show your future roadmap does so they will wait till you get there? "

There is a chance without revealing your roadmap, they "mught" have gone with the current version, like you make a pitch and they like it and want to buy but then you show your roadmap and they are like "oh nice. Let's wait till you reach this" ?

"I would buy if you had this feature..." is one of the most deceptive ways of saying "No thanks, I'm not interested."

This!! I worked for a startup and we were always chasing the "I would buy if you had this feature..." feature for every company who didn't yet buy the product. It was a total mess. And worst of all most companies didn't buy the product once we implemented the exact feature they wanted.