On Mon, 10 Dec 2012 18:17:25 -0800 (PST), marc rosen
So you have a Sawstop? I just want to know if THAT saw can be fitted
with a homemade zero clearance insert. Is there any chance that this
might affect the saferty features in the saw? Would you still be able
to attach the guard system with a ZCI?

Well, going by the description of the SawStop zero clearance insert,
there doesn't seem to be any component part of it that would or would
not affect its operation.
http://www.sawstop.com/zero-clearance-inserts/

Going by the comments of this guy, (3rd down) there seems to be no
reason at all not to make your own.
http://lumberjocks.com/topics/25870