As a chef I can tell you they add sushi vinegar to season rice. which has substantial amount of sugar in it. So you are getting more than just carbs. You will be running in circle with little results. Sorry!!!
Couple things: if you’re not worried about constant ketosis without any break, seems fine. Otherwise if rice is a concern you could do sashimi alone. Other thing is, I think a lot of folks would say due to mercury content it’s maybe advisable to not make it a daily thing.
The rice is going to spike your insulin and negate any positive benefits from the fast.
Why not just have some fish and vegetables? Throw in an egg or two and that’d be a wonderful meal to break a fast.