Wow , we sure know how to make a visual approach complicated. On the Airbus just get rid of the ILS in the FMGS and select the visual approach. You now have the centre line plus a 5 mile fix and surprise surprise a green dot commonly called the "yo-yo" giving a visual 3 degree slope to touch down, provided the to wpt is either the 5 nm fix or the threshold. How hard can we make it? by trying to get too fancy with the FMGS! Remember the KISS principle.