If you are going to hang, I think it is more practical to use an ADS of some sort rather than an extender. PE weights, for instance, can provide a similar amount of force as an extender, but are much less of a hassle, are easier to conceal, and will apply the force to the same tissues you target while hanging BTC - probably your starting angle.
You could, however, just try an extender first completely by itself. Just try your hardest to maximize the time you use it each day. I don’t think this will toughen you up too much for hanging, especially not in your ligaments. Extenders simply do not apply enough force when compared to hanging to cause toughness in your connective tissues that a hanger cannot overcome. And the force they due generate is primarily applied to the tunica, not the suspensory ligaments.
Roots