Flexowriter was VERY before my time. State-of-the-art circa 1980 was the DEC LA120 (DECWriter III), a dot-matrix printing terminal with a logic-seeking printhead that absolutely smoked the neighboring LA36.

There were Selectrics set up as terminals, though, as the mechanism was well-suited for it. I think IBM called it a 2741. I never saw such a beast, though.