Why slow down from the initial approach speed st all? Any precision approach is going to have acres of concrete at the bottom which will give you plenty of space to slow down. Going slowly at DH doesn't improve your eyesight in poor visibility. Also the faster you go the less drift and less vertical speed corrections are required and you also have less time to foul it up.
If a twin turbine plank wing can use the same DH as you then you can use the same speeds as him.