[Ola C]

For a fully enclosed cut you must use dust extraction from underneath. Incra clean sweep inserts are quite good for this as they have openings for the dust to escape. For a cut like this, I attach my vacum hose directly to the router in the router table, no suction box, and it works quite ok with those inserts.

You can make a few relief passes on the table saw to remove most of the waste before routing the final shape on the router table.