Teaching the 3 bead method to students is a wonderful way to get them to product nails with both balance and beauty. However, as time marches on and skills improve, there is nothing wrong with adapting your methods to suit you, and your time, etc as long as you do not sacrifice the quality of your work.
I work 90% of the time using 2 beads. One for the whites and one for the pink body of the nail (exception usually the thumbs). I'm a big girl now and I know how to build in the stress area and apex using this method and it is quick and easy for me.
Techniques for teaching areone thing, and adapting your skills is another. Enjoy playing with it.