I have an outrigger attached to my double length ultra mft bench. It has been attached using 2 sets connectors, 1 set in the upper track took and bench corner. The second set is connected with the lower bench corner hole, and the inside corner of the bench has connectors in both the upper and lower tracks !
It took some work and patience to fit the slide in piece into the lower track, but it was worth the effort. I simply inserted the small diameter end into a drill chuck and used emery cloth to cut the diameter of the slide in piece until it fit.
Once fully assembled, my double length bench with the outrigger on the right side of the cut strip, is absolutely rock solid! My bench , at the right side now measures 48”. Everything that I have put together thus far has been amazing !!