you are screwed up with names, you changed ground. that makes an ac stator dc. it also gives twice the output. a excellent repair but its not floating. honestly you can't float ac period. end of story. ac floats by definition.
so what floats, dc only. the dc output could be considered floating. why because its not steady. when the dc voltage gets to 14.3 the regulator turns on. below 14.3 the regulator is off. the voltage floats with the regulator. 14.3 is the average voltage from the regulator. some times a bit higher other times a bit lower but when its on the average is 14.3v. that's the float. I don't care how many times you check, the frame is 0 with a dc stator. full wave dc ground does not float. on an ac stator you can run 1/2 wave. you float ground with an ac stator. ground is still zero but you can't use it because the ground coming out of the regulator is -7.16. when you float ground you use only the + side of the wave. what this means is ground can't touch the frame. ground floats isolated from the frame.