Of course, a threaded muzzle offers flash hider, suppressor, tuner, etc. options, but are there real advantages to the target crown?

Significantly more intrinsic accuracy? Other factors?

Barrel gurus say the 11 degree crown produces the optimal accuracy. This crown is more obvious with an unthreaded barrel, however a quality threaded barrel also has the 11 degree crown.

Yes, it’s not an either/or choice.
Although like many firearms-related terms, definitions vary some according to who’s using it, but in general the crown is how the very end of the internal rifled bore is finished, whereas muzzle threading is on the outside of the barrel.

As for the advantage of a crowned barrel, the most common reason given for any configuration is that it helps protect the end of the rifling from damage. If a specific type helps with precision that would be a secondary benefit as compared with the traditional purpose. Searching for “firearms barrel crowns” will produce many results that discuss the matter at length.

A muzzle device like a flash hider or brake will protect the rifling even more than something like a shallow crown. That’s a good thing when muzzles get jammed into the dirt during vigorous tactical exercises. (Even then, of course, it’s important to ensure that the device is cleared of any obstruction before shooting.)