When I first morphed my table saw extension RT into and enclosed cabinet (still attached to the TS) I planned ahead for a thicker and wider top. I can't even remember why now but at one point my life would have been easier if I could have clamped to the RT; my extension top's sides were flush. The new top hangs off each side and the front.
I had planned to make the new top myself but, back when Rockler was blowing out their old style tables, I picked up a top and fence at a good price. My original extension RT was about 7/8" in order to fit in a frame that could bolt to TS fence rails. I left that requirement behind awhile ago.
As mentioned in the past I have a close rib structure to prevent sag. Modifying the hole in the Rockler table is a little pesky as the larger Woodpecker hole needs to position the lift within the ribs.
The top connects to the cabinet in 12 places as well as 4 bolts along the TS wing RT top joint. I added some inserts just like my previous table.
I don't have my router cabinet loose every day so I took advantage and did some tweaking on the TS top. It hasn't been touched since the original setup and only the wing edge that bolts to the RT was off a couple thou; quick fix.
I clamp the table in place to do the final set on height so everything is nice and flat.
Attach everything and re-check . . . all is well.