Hope I didn't start this rumor! Bass boost is +6.5dB at 80Hz and diminishes from there.
We tried a 1-band bass EQ in an early prototype (64 steps), and I wasn't pleased. Everyone preferred the on/off switch. Mechanical switches perform best in measurements as well. This experiment gave us the opportunity to try as few or as many levels as we wanted. At +3dB/+6dB/+8dB, the go-to level was still around +6dB. Real-world users simply desired +0 or +6dB, so that's what we built.
Final production samples landed on my desk early this morning, and initial testing looks normal. THD+N @ 1kHz measures better than 0.001%: