Ah ok, I read the manual of 9038 sabre chips yesterday it exposes something called OSF bypass that is supposed to be able to disable the FIR, maybe it's something that will arrive in a future firmware update if possible,, and more options can't hurt.
On another note I see that the MQA version is some 300$ more expensive, is there any other changes beside newer XMOS chipset, and MQA support some have reported that the USB input of the MQA version, sounds better than the older one but I doubt that is possible unless the implementation has changed.