Hi Joe JJ1FJK
I'll be at the Ham Fair and will probably drop by the SOTA booth too. Hope to meet you there!
There is a typhoon right now off Japan http://www.jma.go.jp/en/typh/ not sure where it's headed yet so please take care during the climb. Forecast is rain until Sat, but sunny on Sunday.
Sunrise viewing is a big thing with the Japanese climbers (and tourists) so the summit might be packed! You will probably be hiking up using the Yoshida trail, it is the most popular trail for people comming from Tokyo. It can get crowded but it conveniently ends up on the east side of the crater. There are small structures/buildings here, a shrine, a post office that can protect you from the elements, if needed, but most are in close proximity to the hiking trail.
On the west side of the crater (you can hike around the crater) is a steep hill with a building on top. I think this is the true highest point of Fuji-san. The building is a weather station. Some people use the structure for protection from the wind. If it is not crowded it can be a good place to setup.
Summit is mostly loose volcanic rock. Nothing to support a pole unless you're near a structure.
Goodluck and safe travels.
(not very active w/ SOTA at the moment)