I fished solo from a 14' john for a couple of years and always wanted to be a little further forward. I took a 6gallon milk crate and mounted a piano hinge and plywood top for it, and mounted a swivel seat on that. Still have the crate and not the boat. Placed it so the seat would tilt forward to access the tackle I stored in it and the wind didn't blow it open.Put me just forward enough to be comfortable and let me get my knees around the sides when needed. Keeping the center of gravity has it's good points too.
Creativity is just intelligence fooling around