That FG is very indicative of a high mash temp and higher amounts of cara's. As a general rule of thumb for me a FG of 1.020 is about 160 mash temp. I bet it's done.
I know this is a real newbie question but I am still learning about all the aspect of all grain brewing, including grains.
Are you considering the roasted/dark malts in my recipe the same as a cara's in terms of the unfermentables they bring to a recipe?
Yes. Your grist bill has a major effect on fermentability, mash temp less so.
What could I do next time to make a little more fermentable but maintain the flavor I have achieved. I am pretty happy with how it taste and it fits to the style.