Even though the presenter on the American Woodworking video uses the miter gauge slots for his auxiliary table, there is no need to use this approach. In fact, I do have miter gauge slots on my table, but I did not use them.
Instead, I ripped the plywood into eight 1 inch slats and attached them to the bottom of the 24x24 table. I first attached one cleat to the bottom of the auxiliary table, positioned so that I had the desired overhang (between 2 to 4 inches, I think). I tried to make sure it was parallel to the edge of the auxiliary table.
Once I did that, I removed the bandsaw blade and positioned the auxiliary table on the bandsaw table, marked where I wanted the opposing cleat, removed the table and attached the cleat. All while trying to make sure that the auxiliary table was parallel and perpendicular to the existing table. It took a few tries to where it was sufficiently tight enough. In fact, I waxed the bottom so it would more easily slide, it was that tight. I didn't want any slop
Once I added the side cleats, I added the front cleat, again, making certain that the overhang was sufficient and the table was positioned correctly.
I removed the auxiliary table and reinstalled the bandsaw blade and cut through the auxiliary table from the back. i.e., I slid the auxiliary table along the cleats until the front cleat prevented it from going any further. Because I made a mistake in the placement of the front cleat, I cut further than I intended. (I had to reposition the cleat after I cut the slot for the bandsaw blade, duh).
Next, I cut the slots for the miter gauge and the t-track on the table saw using a dado blade. You want to make sure that there are no screws that will be in the path of the dado blade.
After that, I built the fence using 3/4 baltic birch, screws, glue and triangular support pieces. I added blocks to one end so that my miter gauge would have something secure to attach to.
To lock down the fence once it is set, I use Rockler Universal Fence Clamps
that I picked up on sale on the front and back of the fence.
I do need to create a more elegant solution to clamping the auxiliary table to the bandsaw table than the bar clamps I am currently using. I want something that will not interfere with the table.
I'll try to attach pictures from the bottom so you can see the cleats I am using to position the auxiliary table onto the bandsaw table.