Flash Nikon SB800 and Fuji XH1 and XE3?

[Zababo]

Has anyone tried to connect an X-H1or an X-E3 with a Nikon flash SB800? Is that electronically compatible? 
Shure TTL is probably not ok but in manuel mode, is it useful? What model of transmitter to use?

[itchy shutter finger]

I have a a pair of X-E3's and a slew of legacy dedicated Nikon flashes, specifically, a Nikon SB-50DX, and three Sunpak PZ 5000AF. I also occasionally use a couple of small fill in slaves. 

I nearly never use the SB-50DX, and usually use one or two of the Sunpaks. You're correct that none of these will operate in TTL, but they work excellent in manual and automatic modes. The best part of this whole deal is that I use the supplied EF-X8 flash to trigger whatever array I might have set up. I set the camera to Commander mode to operate the off-camera flashes, or I can set it for TTL. In Commander mode, the EF-X8 DOES NOT interfere with the exposure. In TTL, I can still use something off-camera for a little fill. I am pleasantly surprised this works in bright sunlight up to about thirty feet. While I never needed to do this for a real photo, I used the EF-X8 to fire the Nikon flash with the infrared filter installed to fire two of the Sunpaks. I got the second Sunpak to fire nearly two hundred feet away in bright daylight.

I've been using this setup for about 10 months now, and I'm tracking the shots I missed. So far, I'm up to ZERO missed shots. If this ever fails me, I will consider something else, but I'm real happy with this.

Based on how well all of this works, I think you can set your SB800 to an optical slave mode, mount the EF-X8, set the camera to Commander mode, and flash  away. If you need TTL, just use the EF-X8.

Until you need TTL over thirty feet, or you have interference from other photographers, I think you have all you need for a working setup. 

As I mentioned, I use X-E3's; I don't know if the X-H1 will accept the EF-X8 flash. Based on photos of the X-H1, it looks like it will. If anyone knows better, please comment.

[Zababo]

Thanks a lot itchy. 
Your way with the EF-X8 as trigger, useful on X-E3 as on X-H1, and the SB800 as a slave flash, seems to be the more simple to use. 
Thanks for your experience with that association on XE3.