They're especially useful if you want more definition in low tunings. These strings may need small setup adjustments on your bass.
On S.I.T. exposed core and taper wound strings, the bare or tapered section starts about 1 7/8 to 2 inches from the ball end.
Winding length matters more on extended-range and multi-scale basses than on a standard 4-string, because headstock and tuner geometry vary more. Make sure the taper falls in the right place for your bridge.