consider changing would be to book a place to stay in Mishima for right after the climb. You can take a 1.5 hour bus ride to Mishima right from station 5 of the Fujinomiya trial.
That gives you time to get off the mountain, shower, rest for a bit, and then not be rushed to find dinner if you wanted to eat a celebratory meal.
Something else we didn’t know is that there was a bus that went straight to Mishima, so we got down to the parking lot and had to wait an 1-1.5 hours in the heat for the bus. Would recommend finding out the schedule before climbing so you can time your descent and get directly on the bus.