Well, I've had a bit of experience along these lines, having put activators in a Modulus 6, a custom 5 string, and also a Series setup in a Starfire.
For a Starfire, I say in for a penny, in for a pound. It's really worth opening the bass up and doing a proper shielding job from the get go. It's not as simple as most shielding jobs, but it's really worth it.
For the Alembic process, this thread has a lot of great photos and shows how they do the process at the mother ship. They use the silver shielding paint, which does a great job.
http://club.alembic.com/index.php?topic=7080.0For my bass, I did it locally and went for a door on the backside. Initially, the luthier didn't really get what I was after and made the door too small, but I revisited it years later and we did it right. Serendipitously, the original door was just the right size to mount the Series circuit board. I used copper shielding tape, which is good, but the thickness of the tape causes some problems that are avoided by the use of the paint.
I wouldn't worry about getting too much grief over at the Guild site. They were very supportive of my bass's "evolution".
For the Casady tone, bear in mind that his first Starfire was not an active tone control system (if I recall correctly, the bass was completely passive), but was essentially based on a greatly expanded varitone kind of circuit.
I think the standard activators would sound great on a Starfire, especially with Anniversary electronics.