I've had no issues changing domestic connections on the day at the airport since married fares have come into play - all at WLG). I would have done this at least 5 it 6 times over the past year both outbound and inbound with the last time being in Feb.
Spoke to ground staff after married fares were introduced and they said it would make zero difference to changes It has however resulted in massive changes to connections and the flights that are available - mostly in a negative way.