The FUJI GFX catalog lacks a "serious" telephoto lens.
In fact, the choice stops at the GF250, which corresponds to a 200 on the full frame.
I hope that at least a 400 or 500mm will be built and produced soon, perhaps not too bright otherwise it would be too heavy.
For example a 400f5,6 or a 500f6,3 (naturally with the possibility of mounting the 1,4X): in this way, even the price would not be..."crazy"