Apparently workshops can now staff adjacent facilities with "unique GREMLIN drones", but how exactly does it work? Do facilities that share a corner count as adjacent, or is it only for facilities that share an edge? Can 2 adjacent workshops staff each other? How do different facilities benefit from an adjacent workshop, and are there any that don't benefit at all?
The only adjacency bonuses are exactly like they were in the previous game: directly vertical and directly horizontal. For this reason, you'll want to build any workshops in the middle column of the base, rather than on one of the edges.
Once you've staffed a workshop, you gain access to staff those adjacent rooms with 2 Gremlins that are themselves engineers. This will net you once bonus engineer per workshop.
Obviously, this means that any adjacent facility that can't use engineers (Labs, for instance) will never benefit from workshops.