Maybe I've missed something in the above but, as contingency fuel is 5% of the trip fuel, after the trip fuel has been used (ie. the end of the trip) there's no need for it to be there so, in computer flight planning terms.....it isn't!
At the end of the trip other reserves come into play and contingency fuel is history.
In reality if you are planning to land at/near max landing weight, you need to bear in mind that your contingency fuel probably will/might still be in the tanks.