One of the benefits of later liberations is if the pigeons do get off line they run out of daylight before they are too far away and have to roost therefore saving a bit of energy. If they manage to find a drink and maybe something to eat they can make their way home next day. If they are up early pigeons that get off line can spend much more time trying to find home and then becoming exhausted making them easy prey for predators.
It really depends on the parent birds and the loft environment and how the pigeons 'get on' with the fancier.
With one pair recently I have moved the nest to a new location. The hen laid on the floor behind the loft door so I moved the first egg 4 ft to an opposite corner and the parents continued sitting.
I have heard of fanciers checking if eggs are full and the parents then desert.
If you move them try to give them a box in a similar position, and the same coloured box front, you could also try locking one or both parents in. You will soon know if they are going to continue incubating.
They will sit and try to hatch as many eggs as they can cover, this is sometimes done to try and motivate natural racers.
Do not try and let the "parents" try to rear more than two young birds it would only put undue stress on old and young birds.
I live less than a mile from Ewood Park. I have lived here ten years, was a bit of a vagabond before ling in a few places in UK also Northern Ireland and Germany.
NEHU 2004 NOR 2192 Blue Hen
At my loft in Blackburn, Lancs. it looks like she has been out for some time.
She is in my old rabbit hutch waiting to be claimed.