I’ve done some of what I think this is, working on prem with customers, and I find it funny when I see jobs for FDEs that are somehow all in-office in San Francisco. The whole idea of being forward deployed I take to mean actually deployed.

If you are not issued body armor and K&R insurance FDE seems like the wrong term. (the use of "engineer" for non-PEs is... a fair debate)

the customers are also in san Francisco?

I've done this too, just not under the official FDE title. I've never wanted to end it all so badly before. I felt like a tutor for a bunch of man-babies, who was stuck in a Groundhog Day-esque loop. Heavy breath of relief when the contract ended.