Good question.

Almost always. I have a ZCI for 90 degrees, 45, 7, 3/4" dado and a double 90
for mounting 2 rip blades with a spacer for making 2 sides of a tennon in a
single pass.

For "everything else", I use the stock insert. :-)

Make your own. I used offcuts from some 1/2" cabinet-grade plywood. A couple
of layers of masking tape was all that needed on the bottom to shim them up
to level.

Cheers,

Steve

Thanks everyone for the replies, you have eased my mind. My last
question regarding ZCI's are, do most of you just keep this in all the
time (except when mitering or dadoing of course)? Is there any other
reason to use the stock insert?