This thread may provide some useful info.

Thanks for the link, however it’s incorrect. I ran the tests and found it isn’t bit perfect. 

I didn’t think the thread could be taken as providing a yes / no answer.

I am neither equipped nor sufficiently interested to discuss this, perhaps others will be. 

Neither am I, and my Connects are audibly as good as I need them to be via their analog outputs, and I am pretty sure so would the Port be.

Is the OP claiming that the Port digital out in Fixed level mode is measured by him and found to not be bit perfect?

Yes this is exactly what I found. 

Interesting; the follow up question is the inevitable one. Can this imperfectness be picked out in a sound level matched blind listening test? When compared to another source that is measured to be bit perfect.

That may be an inevitable question for some, but for many others, they just want the product to do what all the previous products did and, what it appears, Sonos says it can do. 

With respect to a listening test, it’s absolutely audible with some material, especially that which requires decoding in the DAC. For example, HDCD content. With an HDCD DAC, this material is decoded properly when fed bit perfectly and sounds great. Without this, the content doesn’t benefit from the technology because the DAC can’t see the HDCD flag on the 16th / least significant bit. 

I know that I did not hear any differences between SACDs played on my then in use high end SACD player and with the lossless CD rips of the same albums on a NAS using the analog outputs of the Connect. Doing careful listening, late at night via quality speakers, so that ambient noise floor was as low as it could be at my home. 

Of course, I am not endowed with golden ears, but my experiences in that testing allied to a preceding decade using audiophile kit convinced me that instrument measured perfection is irrelevant to me. A lack of endowment that I am grateful for, because it is very liberating.

Nevertheless, there may be some that are interested in the fixed level output of the digital output of the Port not being found to be bit perfect; perhaps we will hear from them.