QSC got back to me today. Here's what they had to say:
We have confirmed a difference in the phase response of the 110f inputs vs. the phase response of other QSC input circuits such as the CIML4 card. Keep in mind the 110f was conceived to be used in the meeting room environment rather than the performance audio space. One requirement of that space is a smaller form factor, and we believe this is a result of the miniaturization of the input circuitry.
Note the measured phase shift only applies to 110f analog inputs, so this will not occur on any sources brought in through the network, SIP, USB, etc. If you have applications where you feel this phase response is unacceptable, you could use the analog inputs of a CXDQ amplifier or IO Frame in conjunction with a core 110f, or move to a core model with the CIML4 card such as the Core 510i.
I need to grab a BSS Blu-100 and measure it now to see if it has similar issues.