Fibre Optic Setup

We also have fibre optic for our estate.
You don't have to get it done during the build but it will be easier if it's done as part of the electrical wiring. Whether it is a cost savings doing it after handover will depend on how much an electrician will charge for it as well.
In the least it might be worth you getting the smartbox (home distribution centre) which is the most costly part and is usually put in the garage and allows the connection from the street to the house. I know a few people who didn't get the smartbox installed as part of their build and are now having difficulties getting it done after handover.

We decided to get it done as part of the building electrical work as I want to have it all complete and the after handover quote was not a significant amount cheaper which would mean fiddling around and ensuring someone is home for it which means extra time off work.

I've included extra time off work for waiting for tradies to come and do work as part of my budget, I resent using my annual leave for these sorts of things which could be done as part of construction and I can reserve my annual leave for sitting back and enjoying the house with the family or a holiday