I can't image conditions where you would want/need a front shock on a fatbike. I've got a drop-bar Pugsley with rigid fork that I use on adventure and gravel rides. For summer, I ride
Panaracer Fat B Nimble 26 x 4 tires; typically, I ride 12-13 psi for a 170 lbs rider. Here's the set up:

Finishing the 2019
Heck of the North - Photo credit to Lisa (aka wife)
The Heck of the North is a Northern Minnesota homage to the Hell of the North (Paris Roubaix), we don't have
cobble sectors in the north woods ... we have ATV sectors. These are very rough and rocky sectors, and my fatbike took it great. In the edit below, you can kinda hear the other riders envy my set up (audio quality on my old GoPro wasn't great).
Jump to 5:30 for a sector of very rough ATV trails