James, yes I want it to be able to support a split fence.
Jon, that looks interesting. Thanks for sharing it. You said, "I was going to build", but it sounds like you ended up going a different direction? What happened?
One of the main goals is ease and accuracy of adjustment while keeping the fence at the same angle relative to the bit or blade. That is one of the attributes I like so much about the INCRA approach. The base stays put, and there is no play in the shaft the fence is attached to, but it can still adjust 6 inches or more.
Rockler put their Router Table Top, including fence and accessories on sale at a "I can't pass it up "sale"". As we speak, it is sitting here while I redesign my project around it.
By shimming the "outfeed" fence of the Rockler fence, and adjusting the cutter to the same plane with a straight edge, I can still achieve the same result. A bit more fussy, but not hard to do.
One nice thing about a router table is that all straight lines are still parallel with the bit as Bob on the router workshop continually pointed out, unlike the table saw where the fence being parallel to the blade is critical.
The way the design you presented fails is there isn't much support in the middle, just the width of the end of the board.
The design I presented clamps at each edge of the table. This spreads the support across the entire width of the table.
Rockler's approach doesn't extend completely to the edges, but the slots are far enough apart. The fence provides the "Tee Bolt" slots and a position for tape measure mounting and fence stops, so it is acceptable.