I visited Okinawa island in March last year. According the locals, March-April would be the best time to visit and explore the island in order to avoid winter cold, summer hot&humidity, monzoon of May, and typhoons of fall.
The Yanbaru forest is located in the norden part of the island, and Nago is the best place to stay&go further to north. This part of the island is quite remote, and due to the infrequent public transport - which I used to visit Hiji falls protected area, renting a car would be better and more efficient alternative.
It was a bit rainy day, however for visiting of subtropical rain forest it was an appropriate choice...
I like very much such areas, and I can compare my experience to Laurisilva of Madeira, or in a certain extent also to beech forests of Slovakia (both are WHS). So, I enjoyed my visit a lot, but I have to admit that no everyone would enjoy seemingly boring densely forested areas with a minimum of viewpoints or spectacular flora and fauna.
In the summary, I strongly support the inscription to protect the forested area inhabited by numerous endemic species that might be endangered mainly by military preasures in the area.