Will TankBoost give the same flow and pressure on the ground floor as the top floor in my property when an outlet is opened?

No, because water pressure decreases by 0.1 bar for every meter it travels upwards, starting with a higher-pressure rating at the ground floor (or point of installation) delivers better water pressure at the highest point in the system. The performance at each outlet will depend on the location in the system and any restrictions in place.