Although I haven't heard of some of them, people have used date, muscovado and sucanant sugurs in recipes before.
The the thing about using interesting sugars is that purer, more refined, the sugar (like plain white table sugar) the less flavor is imparted, because it is converted to alcohol.
I'll use mollasses as an example is that a percentage of it is fermentable, meaning that the purest sugar content will be converted to alcohol, leaving only the "impurities" the dark burnt caramel/sulfur that you think of with that stuff as flavor.
It's the same with brown sugar (which is really mollases added to table sugar), the darker Belgian candy sugars, those un-refined mexican and chinese sugars and really even honey all will work the same way. The "pure" sugar will become alcohol leaving behind the unfermentable "flavors" behind.
Also that's why we make or use different grades of belgian sugars, going from clear to dark...they are just really the same stuff boiled until it begins to caramelize (maillard reaction) and that is what adds flavor.
Most of those will have their own unique contribution of flavor. I'm really intrigued with the japanese black sugar...but that might just be something died with squid ink or something and not really ave any different flavor.
So it's worth playing around.
Like my snazzy new avatar? Get Sons of Zymurgy swag, here, and brew with the best.
Revvy's one of the cool reverends. He has a Harley and a t-shirt that says on the back "If you can read this, the bitch was Raptured. - Madman
I gotta tell ya, just between us girls, that Revvy is HOT. Very tall, gorgeous grey hair and a terrific smile. He's very good looking in person, with a charismatic personality... he drives like a ****ing maniac! - YooperBrew