I'm confused about why exactly you wouldn't use both brakes. You'd have to be incredibly numb to your bike not to be able to tell when your rear is about to lock. For that matter, it isn't even really a very big deal most of the time when it does on a straight away.
I pretty much always use the rear brake if I don't have to stop in a hurry, and then when I do have to stop in a hurry I use them in concert. Why wouldn't you use all the available breaking power if you want to stop?
Stuff, as well as things