More layers don't really do a one size fits all job. Everything is affected differently unless it's the exact same way it was before for example.
Some of the fattest basses are in mono, stereo and/or one layer carefully tuned to proper parameters.
Use a gritty'ish mid bass for the movement and key changes (boost the clarity of this with a EQ) and then the sub bass should be sustained (not jumping around in keys) to keep the energy and movement correct of the whole bassline, but obviously don't go off-key and think of it as a simple layer to boost the low-end for a complete bass sound. Try sidechain compression or something. Learn more how to work with low frequencies to get the best outcome!