Running a nickel edge test on the seam tells you fast if it's tight.

Clamp spots have burned me more times than I can count, and I still act surprised every single time like the jig personally betrayed me. First thing I check is whether the box is actually racked or if my bench just isn't flat, because a twist in the table will lie to you all day. Then I measure both diagonals and check that the clamp pressure isn't bowing the 5/8 ply, since maple ply loves to flex if you crank down on the middle. Flip the box over and see if the gap follows it, that tells you if it's the box or the jig.

Oh man, the wrong controller thing is brutal. Reminds me of the time my sister spent 20 minutes yelling at the TV because the sound was gone, and it turned out she had muted it by sitting on the remote. We still bring that up at every family dinner. At least Dave caught it before hour three, so you only lost two hours instead of the whole night.