It really depends on if you need milk for the house as well as raising kids. I take my kids off their mum just after disbudding - usually day 4/5, maybe leave another day if boys have been ringed. It is also easier to put them onto the bottle if you manage to be there for the birth and then milk some colostrum from the dam straight into a bottle and feed the kids. They will then take that and your big worry of them getting their first lot of colostrum is dealt with. They will then also have more time/energy etc to find the milk bar themselves. 1st kidders need some supervision and maybe some holding as they may be a bit fidgety.
By starting to milk out twice per day from 4 - 5days onwards the milk supply will also stay higher for longer, as the natural reduction as happens when the kids take less and les milk, is not happening. So your nanny is producing more milk for longer for you (with adequate feed intake of course). - And I guess that's what you want a goat for - milk supply for the house.
Also by bottlefeeding the kids you know how much milk they have every day, and you can make sure that all kids get enough. And you can let kkids out with ther dams in the same field from about 4 weeks onwards easily, they will by then come to you for their milk rather than the dam.
Milking out also helps prevent mastitis, especially if you have single kid and a heavy milker.
So better all round I think... especially if you have lots of visitors who would help with feeding the kids/milking the nanny etc etc