No; you're quite correct. Unused power gets shunted back through the stator (not ground) and adds to the heat stress on the windings, hastening insulation breakdown.As for function over cosmetics, I am not an electricalengineer so I might be wrong with this.....unless you have modified you regulator (mine has been upgraded to a sh775 regulator) the old bikes use a shunt type regulator which puts all extra current to ground. So technically by putting a LED headlight on your actually putting more strain on your electical system. Again I might be wrong with that statement.
In the past couple of years I was quite surprised to find that PM alternators are still commonly fitted, and it's largely luck that dictates whether the design is good or bad in the long run. On the face of it, there's not much difference between the stator windings of a 1980 GS850 and a modern Ducati, Aprilia or Triumph using the same system.I think this theory only applies to magneto systems, not modern alternator-and-electronic-regulator systems.