The cast iron extension table that the new cast iron Sawstop router table replaced? I bought the Incra LS Positioner and fence system and am adding the router fence and joinery package to the system. For this to have a good working range for the router I needed to mount the router table next to the cabinet table to the right of the saw blade. Turns out the router table insert only has mounting holes on one side of the cast iron so attaching the extension table after router table isn't possible without drilling new holes which I'm not really comfortable with at this point. Holding and positioning the cast iron table with this not quite recovered shoulder was a stretch in more than one way. My PT lady wasn't so thrilled about it either although I'm ahead of schedule in recovery. Anyway I need to store that extension table somewhere and I'm guessing the flatter the better and away from any possible moisture but my main concern is how likely is it that it could warp in time? At this point the only place to keep it out of the way and reasonable flat is on my clamp rack shelf which is basically a 3/4" plywood shelf that will more than cover the length and width of the table with about 3" extra front and side. There is a vertical divider under that shelf so it has plenty of support and my straight edge shows it's flat. The basement shop is conditioned and humidity seldom rises over 40% even with this extremely wet year we've had and it seems like it will continue as such at least for the time being. I think it was the 3rd wettest year here since they started recording th weather. Point being humidity and temperatures aren't an issue.