Hi Mike, welcome and congratulations on acquiring an Alembic guitar.
Alembic won't fit a CAE preamp; it's not compatible with Alembic electronics. It's designed to be an add on to a conventional, passive guitar.
So you have two very different choices: sticking with Alembic electronics or abandoning them.
If the Electrum has a summing amp (which it probably has, but I don't know), Alembic might be able to add an effects loop. Or you could follow Dave's advice and upgrade to Tribute/Further electronics, where each pickup has two preamps, six in total! I would advise you to stick with Alembic electronics, they are the best.
Mark