I fully understand the fact that you were told by one Marantz rep that it wasn't possible to bypass the Marantz's internal dac, but since then you must have read quite a few forum members rebuttals of what that rep said, and/or questioning/expressing doubts about what's been said For the benefit of other members who might not have investigated this alleged issue, I would quote the following, from that AVSF (surely you read it, as you participated), just so they can have a more balanced view on this alleged issue.
First, see their resident expert (I read a lot of his stuff, and I have the impression that he's probably an "insider", and have viewed a lot of service manuals, and evidently knows how to read schematics) bigguyca's comment:
The "OFFICIAL" 2022-23 MARANTZ AV 10 Flagship DIRAC Processor Owners' Thread (!!!-READ THE 1st PAGE-!!!) | Page 31 | AVS Forum
In response to the original question:
and the following shows one memember took the time to investigate further, with the help of a dealer:
Marantz AV10 2-Channel w/ External DAC | Page 2 | AVS Forum
Again, the reason I took the time to do this post is, so other members, owners or potential owners of the AV10 can have a more complete picture, not just the one you posted so far. It is not really directed to you as such, as I am sure you have good intention and just want to share what you know on this topic.
Here's one post about how a member questioned the rep(s), he talked to 2 reps apparently further:
Marantz AV10 2-Channel w/ External DAC | AVS Forum
You can see in the quote that those reps are not really sure, the part about the crossover thing is sort of a straw man argument, though the rep was at least thinking logically. On that suggestion, I got a response from Marantz that it was explainable as to how they could do the small/crossover without "digitizing". Actually Gene found that similar thing in his review of one of the old Denon flagship, that it was able to do small and crossover without the signal being digitized (not too relevant but just want to mention it in case someone might be interested to know).
Another post there where the member expressed doubt:
Marantz AV10 2-Channel w/ External DAC | AVS Forum
Another post, that seem to be directed to the one above, about doubting the Marantz rep's as he's getting inconsistent responses too:
Marantz AV10 2-Channel w/ External DAC | Page 2 | AVS Forum
Despite what has been said, you still seem to insist on the untruth:
Below is direct quote from your post on AVSF:
@m. zillch then explained to you that you might be wrong, yet your mind seems to be made up just because of one response you got from one Marantz customer rep, and ignore others. That was then, and now, after I took the time to find you more relevant information originated from a product manager who most likely knows more than the first line customer support reps, you still seem so sure that you, and/or that particular Marantz rep is correct and everyone else including Gene, Amir, and others are wrong.