I wouldn't expect bubs head to engage before labour starts seeing as you have had a bub before. Even if they say it has there is a chance it can pop up and down anyway. Just one of the normal things that happens once you body has done it before.

Where I work we encourage everyone to come in once their waters break. Usually just to check everything out and send them home again but each hospital is different and its much nicer to labour at home before heading in to hospital where there is increased chances of intervention. I was just thinking if they are so concerned about cord prolapse that if your waters broke it probably would be better to head in to be assessed and if bub is in a desirable position then they should be able to send you home again for a while (unless there are other reasons not to)