When I was doing the swap to the toyo-denso I read somewhere that you could do something like that, although they took it apart and did it internally, IIRC.

The whole point of running the sense wire to the battery is that it will tell the alternator what the voltage is after all of the power draws such as your ignition, lights, electronic accessories, etc.

Not sure what your plans are for your car. On a drag car it may not make much difference if you are hooking it to a battery charger between runs and not using an electric water pump or fuel pump and the like, and your only power draw is the ignition. On a street car though, by the time you add up running a hot stereo, headlights, ignition, A/C and all of that you may actually be seeing very poor voltage going toward recharging the battery.

If I was to set up a car, I would run it to the battery regardless. Oh, one thing that doesn't come up often in this discussion, on some toyota units the dummy light wire also serves as the trigger wire. Mine would not charge at all until I wired it in.