Excuse the complete ignorance, but I'm in Wales and don't really think it's a "thing" here (or certainly not that I'm aware of anyone doing anyway).
I've seen lots of threads on here about deferring a place for a summer baby, a quick Google hasn't really explained, how does this work? Do you just say you'd prefer the child to stay in private nursery rather than do the reception year, or does the child join the year group behind them? If the latter, when do they then catch up, do they have to skip a year?
In Wales we have a scheme called Rising 3, whereby dc can go to school nursery the term after they are 3, so we seem to be doing the complete opposite to England.