Thanks - these answers are consistent with my inability to find useful information on the subject anywhere else lol.

And, no, I will not be climbing in winter

I made a visit and climb up Fujinomiya trail this August. Conditions at the summit were complete whiteout, no visibility at all and thunderstorms coming soon, so I didn't really get to enjoy my time up there, do Ohachimeguri, visit the post office, or enjoy views at all. I think I'd like to go again, but only if I can figure out how to go with better weather conditions.

I thought I would try to plan around typical weather patterns, but if that is not possible, then planning around crowds might make more sense.