I have a 2015 450 and the spigot and adjusting valve for the wash basin in the non-owners heads are bulkhead mount with spigot and mixing valve separate units. Other than the one for like $250 on the beneteau repair parts
website I've never been able to find a replacement. Even searched a bunch of French plumbing
sites with no luck.
And there is no room to mount a normal through the counter-top unit. Hopefully someone has found a source.