Is the Duke rank ability currently implemented in the game?

"Duke
-=-=-=-=-=-=-=-
Dukes were the rulers of the provinces and the superiors of the counts in the cities and later, in the feudal monarchies, the highest-ranking peers of the king.
Vote Power: 10
*+10% profit on market sales.
*Can propose new laws"

There are no votes or laws and I'm not sure what number the game uses for "market sales".

-Captain D

Vote power as well nation control specific abilities are not yet enabled. They just exist there as a pre-sketch for the forthcoming nation control feature.

What about the +10% market sales? How does that work?

Your nation needs to control a port to get the 10 % extra. It will only count in that port. For example I control Gasp. Therefore when my Hawkers come to port they sell at the normal rate plus 10 % bonus for being one of these (Governor/Duke/King) . I like King the best, lol. A full fleet of five has 300 cargo. Normally you get 10 gold for each cargo of tobacco, which would be 10 times 300 cargo equaling 3000 gold. With the 10 % bonus it actually comes up "
You have sold 60 crates of tobacco for 660 Gold coins.

You have sold 60 crates of tobacco for 660 Gold coins.

You have sold 60 crates of tobacco for 660 Gold coins.

You have sold 60 crates of tobacco for 660 Gold coins.

You have sold 60 crates of tobacco for 660 Gold coins."
For a total of 3300 gold. 10 % extra!

Now you know why Kanoni-Baramas is so good for Wales who have the rank necessary to profit.
Same with Prote-Chalkos for Malaysia.
Seaglory-New land for Barbados

Besides vote power, new laws and port tax, all other bonuses are activated.