I had some initial successes getting ChatGPT (3.5 and then 4) to roleplay interesting and dynamic characters. Within the first few months of release results degraded significantly - characters avoid confrontation, apologize at the drop of a hat, and are averse to any action or statement that doesn't 'help' the user. Makes it difficult to, say, have a passionate argument with Napoleon which pits his youthful revolutionary ideals against his rise to absolute power, when the 'great man' folds the moment he doesn't receive positive feedback.
I'm very interested in seeing these experiments in unrestricted models of similar power, when they become available.