Demineralised Water makeup in Boilers of Power Plant

In standard power plant, having boiler pressure > 80kg/cm² ; D.M Water is used. Generally makeup water is added in hot-well of condenser where steam condensed ( after expansion in steam turbine ) is extracted . I would like to know whether make-up water at higher (>atmospheric) temperature can be added without compromising water quality ? Idea is hot make-up water may improve heat rate of power plant by extracting waste heat at some other point to heat up the make-up water & thus saving fuel.😲