We forwarded your question to Centerpointe and here is their response:
We recommend leaving bass boost features off, both because they don't help and also because in some cases they can cause distortion on the low end which is not good for the Holosync signal.
Sometimes the reason behind this question is that people think they need to audibly hear the Holosync hum in order for it to work so they boost the bass. As you know, Holosync will work fine even if you're not audibly detecting it.
Short answer: it's best to keep a relatively flat eq setting for Holosync and not over boost the low end.
All the best!