EMG pickups are interchangeable, for the most part, within each shell size. At least SGD shared pinouts with them.
I tried doing a modular preamp situation like this with my homemade Modulus body, but it got out of hand pretty quickly.
I guess once you go whole hog and get S II electronics or a Superfilter, then the other stuff becomes superfluous, so for the Alembic situation, there's not as great a need. Also, most Alembic pickups have a pretty similar sound. It's not like going from a lipstick pickup to a MM pickup.