Mike Henry wrote:

Is it really necessary to grind the table perfectly flat before tackling the
mag chuck?

I also have a KO Lee grinder (S714) and have only been planning to dress the
top surface of the chuck. Gotta resolve a scalloping problem first, though,
and that's long overdue.

Before you grind in a chuck, make sure the table is free of burrs and clean it
meticulously, then put the chuck on UPSIDE DOWN and take a cleanup pass over the
bottom, and THEN turn it right side up and loosely bolt it down. Then get out
your dial indicator and set the long fence on the mag chuck so it sticks above
the rear edge of the chuck, and indicate on the fence and adjust the position
until the chuck is oriented correctly and where you want it, and only then
should you grind in the top face.

Quoting from memory from a KO Lee book I have somewhere -- GWE