I built a box-frame 6 foot fence for my table saw, for cutting plywood.
Biscuit four boards into a tube about 6" square, then joint/plane it to
be flat and true. My regular fence has holes for screws through which I
attach it. Given that, and roller stands, I can do full sheets of
plywood on my 10" contractors saw.

I've done the router trick too, to clean up an edge from a circular saw,
using some other sheet of plywood as the straight edge. A good plywood
blade in the TS makes that unneeded, but it does work when you're
cleaning up the saw marks from hardwood edges or rough cuts