This, but it weighs 14 pounds. 800mm f/6.7

Less insane is this. Only 10 pounds. 600mm f/5.6

There's a mirror 1000mm f/8, if you don't care about the bokeh.

https://www.hasselblad.com/de-de/x-system/accessories/xh-lens-adapter

& HC 4.5/300mm

should work with leaf shutter and AF

Curious what is the longest telephoto lens I can get? Don't really care if I need to use electronic shutter, as I'm only shooting static landscapes. Manual focus is fine. Corner to corner sharpness is highly desired though. Aperture pass though is a nice to have, but not a deal breaker. Basically I'm looking for something which can match Fuji's upcoming 500 5.6 lens for their GFX line up

Thanks!

X2d 35-75mm

X2D 35-75mm

There is another option.  Instead of waiting for the alert - I ordered the 38V from B&H on Jan 18 - backordered.  They don't charge your credit card until the item is shipped.  Mine was shipped on Feb 28, and I didn't have to fight others who were waiting for the alert.  I know they were sold out almost immediately.  If you get your lens from another source, you can always cancel your order (with B&H).

and is Maxcast a member? If so have they had there access here compromised?

Thx for the tip Eyelike - I'll do that:

Thanks Ian,
Yes I will likely be tethering for client shoots, but there may be times I will need to work faster and just be going off the screen. The contrast makes shooting contrasty scenes very difficult. I hope they do an update which allows profiles for less contrast and to calibrate the screen, unlikely though. Will just be one of those things you get used to overtime.

As far as I am aware neither Dave nor his "son" are members here FYI