Mines fils from a combi. But from what you;re saying, and basic physics principles, that by putting on a smaller tap it'll creat more pressure and look like more is coming out, but my bath wont fill any quicker? That makes sense.
But, and correct me if I'm worng, I cant alter pressure, but can alter flow? What I want is the water to flow as much as poss. At the moment it takes 15mins to fill a bath. Maybe thats not over average. It just seems like ages