Congratulations Matt, I look forward to your thoughts on the 800 pf when you have had time getting used to it.
Recently we went on an overseas holiday and I was looking for something lighter than the Z 9 and lens to take, mainly due to weight restrictions for carry on. I ended up purchasing a Fujifilm X-H2S and 150-600mm lens. The combo worked well on our trip, and I've been using it quite a lot recently. I do have a couple of issues with the AF compared to the Z 9.
I should also have an 800 pf early next week. I do have some concerns with the 5mtr MFD. I also have the Z 100-400 which I use with a Z fc plus 1.4tc. The MFD is amazing with this combo. I've even photographed very small native orchids while out photographing birds. It's a very flexible lens. I did consider taking the kit on our overseas trip, but I preferred to have a body which had no VF blackout between shots.